Merge pull request #5590 from github/sauyon/java-spring-errors

Add models for Spring validation.Errors

java/change-notes/2021-04-02-add-spring-validation-errors.md

@@ -0,0 +1,2 @@
+lgtm,codescanning
+* Added additional taint steps modeling the Spring `validation.Errors` class (`org.springframework.validation.Errors`).

java/ql/src/semmle/code/java/dataflow/ExternalFlow.qll

@@ -86,6 +86,7 @@ private module Frameworks {
   private import semmle.code.java.frameworks.Optional
   private import semmle.code.java.frameworks.spring.SpringHttp
   private import semmle.code.java.frameworks.spring.SpringUtil
+  private import semmle.code.java.frameworks.spring.SpringValidation
   private import semmle.code.java.frameworks.spring.SpringWebClient
   private import semmle.code.java.frameworks.spring.SpringBeans
   private import semmle.code.java.security.ResponseSplitting

java/ql/src/semmle/code/java/frameworks/spring/Spring.qll

@@ -34,6 +34,7 @@ import semmle.code.java.frameworks.spring.SpringRef
 import semmle.code.java.frameworks.spring.SpringReplacedMethod
 import semmle.code.java.frameworks.spring.SpringSet
 import semmle.code.java.frameworks.spring.SpringUtil
+import semmle.code.java.frameworks.spring.SpringValidation
 import semmle.code.java.frameworks.spring.SpringValue
 import semmle.code.java.frameworks.spring.SpringXMLElement
 import semmle.code.java.frameworks.spring.metrics.MetricSpringBean

java/ql/src/semmle/code/java/frameworks/spring/SpringValidation.qll

@@ -0,0 +1,25 @@
+/** Definitions of flow steps through utility methods of `org.springframework.validation.Errors`. */
+
+import java
+private import semmle.code.java.dataflow.ExternalFlow
+
+private class SpringValidationErrorModel extends SummaryModelCsv {
+  override predicate row(string row) {
+    row =
+      [
+        "org.springframework.validation;Errors;true;addAllErrors;;;Argument[0];Argument[-1];taint",
+        "org.springframework.validation;Errors;true;getAllErrors;;;Argument[-1];ReturnValue;taint",
+        "org.springframework.validation;Errors;true;getFieldError;;;Argument[-1];ReturnValue;taint",
+        "org.springframework.validation;Errors;true;getFieldErrors;;;Argument[-1];ReturnValue;taint",
+        "org.springframework.validation;Errors;true;getGlobalError;;;Argument[-1];ReturnValue;taint",
+        "org.springframework.validation;Errors;true;getGlobalErrors;;;Argument[-1];ReturnValue;taint",
+        "org.springframework.validation;Errors;true;reject;;;Argument[0];Argument[-1];taint",
+        "org.springframework.validation;Errors;true;reject;;;ArrayElement of Argument[1];Argument[-1];taint",
+        "org.springframework.validation;Errors;true;reject;;;Argument[2];Argument[-1];taint",
+        "org.springframework.validation;Errors;true;rejectValue;;;Argument[1];Argument[-1];taint",
+        "org.springframework.validation;Errors;true;rejectValue;;;Argument[3];Argument[-1];taint",
+        "org.springframework.validation;Errors;true;rejectValue;(java.lang.String,java.lang.String,java.lang.Object[],java.lang.String);;ArrayElement of Argument[2];Argument[-1];taint",
+        "org.springframework.validation;Errors;true;rejectValue;(java.lang.String,java.lang.String,java.lang.String);;Argument[2];Argument[-1];taint"
+      ]
+  }
+}

java/ql/test/library-tests/frameworks/spring/validation/Test.java

@@ -0,0 +1,78 @@
+import org.springframework.validation.Errors;
+
+class ValidationErrorsTest {
+  Object source() { return null; }
+
+  Errors sourceErrs() { return (Errors)source(); }
+  Errors errors() { return null; }
+
+  void sink(Object o) {}
+
+  void test() {
+    Errors es0 = errors();
+    es0.addAllErrors(sourceErrs());
+    sink(es0); // $hasTaintFlow
+
+    sink(sourceErrs().getAllErrors()); // $hasTaintFlow
+
+    sink(sourceErrs().getFieldError()); // $hasTaintFlow
+    sink(sourceErrs().getFieldError("field")); // $hasTaintFlow
+
+    sink(sourceErrs().getGlobalError()); // $hasTaintFlow
+    sink(sourceErrs().getGlobalErrors()); // $hasTaintFlow
+
+    Errors es1 = errors();
+    es1.reject((String)source());
+    sink(es1); // $hasTaintFlow
+
+    Errors es2 = errors();
+    es2.reject((String)source(), null, "");
+    sink(es2); // $hasTaintFlow
+
+    Errors es3 = errors();
+    es3.reject((String)source(), null, "");
+    sink(es3); // $hasTaintFlow
+
+    {
+      Errors es4 = errors();
+      Object[] in = { (String)source() };
+      es4.reject("", in, "");
+      sink(in); // $hasTaintFlow
+    }
+
+    {
+      Errors es5 = errors();
+      es5.reject("", null, (String)source());
+      sink(es5); // $hasTaintFlow
+    }
+
+    Errors es6 = errors();
+    es6.reject((String)source(), "");
+    sink(es6); // $hasTaintFlow
+
+    Errors es7 = errors();
+    es7.reject("", (String)source());
+    sink(es7); // $hasTaintFlow
+
+    Errors es8 = errors();
+    es8.rejectValue("", (String)source(), null, "");
+    sink(es8); // $hasTaintFlow
+
+    Errors es9 = errors();
+    Object[] in = {source()};
+    es9.rejectValue("", "", in, "");
+    sink(es9); // $hasTaintFlow
+
+    Errors es10 = errors();
+    es10.rejectValue("", "", null, (String)source());
+    sink(es10); // $hasTaintFlow
+
+    Errors es11 = errors();
+    es11.rejectValue("", (String)source(), "");
+    sink(es11); // $hasTaintFlow
+
+    Errors es12 = errors();
+    es12.rejectValue("", "", (String)source());
+    sink(es12); // $hasTaintFlow
+  }
+}

java/ql/test/library-tests/frameworks/spring/validation/options

@@ -0,0 +1 @@
+//semmle-extractor-options: --javac-args -cp ${testdir}/../../../../stubs/springframework-5.3.8

java/ql/test/library-tests/frameworks/spring/validation/test.ql

@@ -0,0 +1,52 @@
+import java
+import semmle.code.java.dataflow.DataFlow
+import semmle.code.java.dataflow.TaintTracking
+import TestUtilities.InlineExpectationsTest
+
+class ValueFlowConf extends DataFlow::Configuration {
+  ValueFlowConf() { this = "qltest:valueFlowConf" }
+
+  override predicate isSource(DataFlow::Node n) {
+    n.asExpr().(MethodAccess).getMethod().hasName("source")
+  }
+
+  override predicate isSink(DataFlow::Node n) {
+    n.asExpr().(Argument).getCall().getCallee().hasName("sink")
+  }
+}
+
+class TaintFlowConf extends TaintTracking::Configuration {
+  TaintFlowConf() { this = "qltest:taintFlowConf" }
+
+  override predicate isSource(DataFlow::Node n) {
+    n.asExpr().(MethodAccess).getMethod().hasName("source")
+  }
+
+  override predicate isSink(DataFlow::Node n) {
+    n.asExpr().(Argument).getCall().getCallee().hasName("sink")
+  }
+}
+
+class HasFlowTest extends InlineExpectationsTest {
+  HasFlowTest() { this = "HasFlowTest" }
+
+  override string getARelevantTag() { result = ["hasValueFlow", "hasTaintFlow"] }
+
+  override predicate hasActualResult(Location location, string element, string tag, string value) {
+    tag = "hasValueFlow" and
+    exists(DataFlow::Node src, DataFlow::Node sink, ValueFlowConf conf | conf.hasFlow(src, sink) |
+      sink.getLocation() = location and
+      element = sink.toString() and
+      value = ""
+    )
+    or
+    tag = "hasTaintFlow" and
+    exists(DataFlow::Node src, DataFlow::Node sink, TaintFlowConf conf |
+      conf.hasFlow(src, sink) and not any(ValueFlowConf c).hasFlow(src, sink)
+    |
+      sink.getLocation() = location and
+      element = sink.toString() and
+      value = ""
+    )
+  }
+}

java/ql/test/stubs/springframework-5.3.8/org/springframework/context/MessageSourceResolvable.java

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2002-2017 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context;
+
+public interface MessageSourceResolvable {
+  String[] getCodes();
+
+  default Object[] getArguments() {
+    return null;
+  }
+
+  default String getDefaultMessage() {
+    return null;
+  }
+}

java/ql/test/stubs/springframework-5.3.8/org/springframework/context/support/DefaultMessageSourceResolvable.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright 2002-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.context.support;
+
+import java.io.Serializable;
+import org.springframework.context.MessageSourceResolvable;
+import org.springframework.lang.Nullable;
+
+public class DefaultMessageSourceResolvable implements MessageSourceResolvable, Serializable {
+  public DefaultMessageSourceResolvable(String code) {}
+
+  public DefaultMessageSourceResolvable(String[] codes) {}
+
+  public DefaultMessageSourceResolvable(String[] codes, String defaultMessage) {}
+
+  public DefaultMessageSourceResolvable(String[] codes, Object[] arguments) {}
+
+  public DefaultMessageSourceResolvable(
+      @Nullable String[] codes, @Nullable Object[] arguments, @Nullable String defaultMessage) {}
+
+  public DefaultMessageSourceResolvable(MessageSourceResolvable resolvable) {}
+
+  public String getCode() {
+    return null;
+  }
+
+  @Override
+  public String[] getCodes() {
+    return null;
+  }
+
+  @Override
+  public Object[] getArguments() {
+    return null;
+  }
+
+  @Override
+  public String getDefaultMessage() {
+    return null;
+  }
+
+  public boolean shouldRenderDefaultMessage() {
+    return false;
+  }
+
+  @Override
+  public String toString() {
+    return null;
+  }
+
+  @Override
+  public boolean equals(@Nullable Object other) {
+    return false;
+  }
+
+  @Override
+  public int hashCode() {
+    return 0;
+  }
+
+  protected final String resolvableToString() {
+    return null;
+  }
+}

java/ql/test/stubs/springframework-5.3.8/org/springframework/util/ObjectUtils.java

@@ -1,50 +1,188 @@
-// Generated automatically from org.springframework.util.ObjectUtils for testing purposes
+/*
+ * Copyright 2002-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
 
 package org.springframework.util;
 
 
-abstract public class ObjectUtils
-{
-    public ObjectUtils(){}
-    public static <A, O extends A> A[] addObjectToArray(A[] p0, O p1){ return null; }
-    public static <E extends Enum<? extends Object>> E caseInsensitiveValueOf(E[] p0, String p1){ return null; }
-    public static Object unwrapOptional(Object p0){ return null; }
-    public static Object[] toObjectArray(Object p0){ return null; }
-    public static String getDisplayString(Object p0){ return null; }
-    public static String getIdentityHexString(Object p0){ return null; }
-    public static String identityToString(Object p0){ return null; }
-    public static String nullSafeClassName(Object p0){ return null; }
-    public static String nullSafeToString(Object p0){ return null; }
-    public static String nullSafeToString(Object[] p0){ return null; }
-    public static String nullSafeToString(boolean[] p0){ return null; }
-    public static String nullSafeToString(byte[] p0){ return null; }
-    public static String nullSafeToString(char[] p0){ return null; }
-    public static String nullSafeToString(double[] p0){ return null; }
-    public static String nullSafeToString(float[] p0){ return null; }
-    public static String nullSafeToString(int[] p0){ return null; }
-    public static String nullSafeToString(long[] p0){ return null; }
-    public static String nullSafeToString(short[] p0){ return null; }
-    public static boolean containsConstant(Enum<? extends Object>[] p0, String p1){ return false; }
-    public static boolean containsConstant(Enum<? extends Object>[] p0, String p1, boolean p2){ return false; }
-    public static boolean containsElement(Object[] p0, Object p1){ return false; }
-    public static boolean isArray(Object p0){ return false; }
-    public static boolean isCheckedException(Throwable p0){ return false; }
-    public static boolean isCompatibleWithThrowsClause(Throwable p0, Class<? extends Object>... p1){ return false; }
-    public static boolean isEmpty(Object p0){ return false; }
-    public static boolean isEmpty(Object[] p0){ return false; }
-    public static boolean nullSafeEquals(Object p0, Object p1){ return false; }
-    public static int hashCode(boolean p0){ return 0; }
-    public static int hashCode(double p0){ return 0; }
-    public static int hashCode(float p0){ return 0; }
-    public static int hashCode(long p0){ return 0; }
-    public static int nullSafeHashCode(Object p0){ return 0; }
-    public static int nullSafeHashCode(Object[] p0){ return 0; }
-    public static int nullSafeHashCode(boolean[] p0){ return 0; }
-    public static int nullSafeHashCode(byte[] p0){ return 0; }
-    public static int nullSafeHashCode(char[] p0){ return 0; }
-    public static int nullSafeHashCode(double[] p0){ return 0; }
-    public static int nullSafeHashCode(float[] p0){ return 0; }
-    public static int nullSafeHashCode(int[] p0){ return 0; }
-    public static int nullSafeHashCode(long[] p0){ return 0; }
-    public static int nullSafeHashCode(short[] p0){ return 0; }
+import org.springframework.lang.Nullable;
+
+public abstract class ObjectUtils {
+  public static boolean isCheckedException(Throwable ex) {
+    return false;
+  }
+
+  public static boolean isCompatibleWithThrowsClause(
+      Throwable ex, @Nullable Class<?>... declaredExceptions) {
+    return false;
+  }
+
+  public static boolean isArray(@Nullable Object obj) {
+    return false;
+  }
+
+  public static boolean isEmpty(@Nullable Object[] array) {
+    return false;
+  }
+
+  public static boolean isEmpty(@Nullable Object obj) {
+    return false;
+  }
+
+  public static Object unwrapOptional(@Nullable Object obj) {
+    return null;
+  }
+
+  public static boolean containsElement(@Nullable Object[] array, Object element) {
+    return false;
+  }
+
+  public static boolean containsConstant(Enum<?>[] enumValues, String constant) {
+    return false;
+  }
+
+  public static boolean containsConstant(
+      Enum<?>[] enumValues, String constant, boolean caseSensitive) {
+    return false;
+  }
+
+  public static <E extends Enum<?>> E caseInsensitiveValueOf(E[] enumValues, String constant) {
+    return null;
+  }
+
+  public static <A, O extends A> A[] addObjectToArray(@Nullable A[] array, @Nullable O obj) {
+    return null;
+  }
+
+  public static Object[] toObjectArray(@Nullable Object source) {
+    return null;
+  }
+
+  public static boolean nullSafeEquals(@Nullable Object o1, @Nullable Object o2) {
+    return false;
+  }
+
+  public static int nullSafeHashCode(@Nullable Object obj) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable Object[] array) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable boolean[] array) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable byte[] array) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable char[] array) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable double[] array) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable float[] array) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable int[] array) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable long[] array) {
+    return 0;
+  }
+
+  public static int nullSafeHashCode(@Nullable short[] array) {
+    return 0;
+  }
+
+  public static int hashCode(boolean bool) {
+    return 0;
+  }
+
+  public static int hashCode(double dbl) {
+    return 0;
+  }
+
+  public static int hashCode(float flt) {
+    return 0;
+  }
+
+  public static int hashCode(long lng) {
+    return 0;
+  }
+
+  public static String identityToString(@Nullable Object obj) {
+    return null;
+  }
+
+  public static String getIdentityHexString(Object obj) {
+    return null;
+  }
+
+  public static String getDisplayString(@Nullable Object obj) {
+    return null;
+  }
+
+  public static String nullSafeClassName(@Nullable Object obj) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable Object obj) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable Object[] array) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable boolean[] array) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable byte[] array) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable char[] array) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable double[] array) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable float[] array) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable int[] array) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable long[] array) {
+    return null;
+  }
+
+  public static String nullSafeToString(@Nullable short[] array) {
+    return null;
+  }
 }

java/ql/test/stubs/springframework-5.3.8/org/springframework/validation/Errors.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.validation;
+
+import java.util.List;
+import org.springframework.lang.Nullable;
+
+public interface Errors {
+  String getObjectName();
+
+  void setNestedPath(String nestedPath);
+
+  String getNestedPath();
+
+  void pushNestedPath(String subPath);
+
+  void popNestedPath() throws IllegalStateException;
+
+  void reject(String errorCode);
+
+  void reject(String errorCode, String defaultMessage);
+
+  void reject(String errorCode, @Nullable Object[] errorArgs, @Nullable String defaultMessage);
+
+  void rejectValue(@Nullable String field, String errorCode);
+
+  void rejectValue(@Nullable String field, String errorCode, String defaultMessage);
+
+  void rejectValue(
+      @Nullable String field,
+      String errorCode,
+      @Nullable Object[] errorArgs,
+      @Nullable String defaultMessage);
+
+  void addAllErrors(Errors errors);
+
+  boolean hasErrors();
+
+  int getErrorCount();
+
+  List<ObjectError> getAllErrors();
+
+  boolean hasGlobalErrors();
+
+  int getGlobalErrorCount();
+
+  List<ObjectError> getGlobalErrors();
+
+  ObjectError getGlobalError();
+
+  boolean hasFieldErrors();
+
+  int getFieldErrorCount();
+
+  List<FieldError> getFieldErrors();
+
+  FieldError getFieldError();
+
+  boolean hasFieldErrors(String field);
+
+  int getFieldErrorCount(String field);
+
+  List<FieldError> getFieldErrors(String field);
+
+  FieldError getFieldError(String field);
+
+  Object getFieldValue(String field);
+
+  Class<?> getFieldType(String field);
+}

java/ql/test/stubs/springframework-5.3.8/org/springframework/validation/FieldError.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-2018 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.validation;
+
+import org.springframework.lang.Nullable;
+
+public class FieldError extends ObjectError {
+  public FieldError(String objectName, String field, String defaultMessage) { super("", ""); }
+
+  public FieldError(
+      String objectName,
+      String field,
+      @Nullable Object rejectedValue,
+      boolean bindingFailure,
+      @Nullable String[] codes,
+      @Nullable Object[] arguments,
+      @Nullable String defaultMessage) { super("", ""); }
+
+  public String getField() {
+    return null;
+  }
+
+  @Nullable
+  public Object getRejectedValue() {
+    return null;
+  }
+
+  public boolean isBindingFailure() {
+    return false;
+  }
+
+  @Override
+  public boolean equals(@Nullable Object other) {
+    return false;
+  }
+
+  @Override
+  public int hashCode() {
+    return 0;
+  }
+
+  @Override
+  public String toString() {
+    return null;
+  }
+}

java/ql/test/stubs/springframework-5.3.8/org/springframework/validation/ObjectError.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.validation;
+
+import org.springframework.context.support.DefaultMessageSourceResolvable;
+import org.springframework.lang.Nullable;
+
+public class ObjectError extends DefaultMessageSourceResolvable {
+
+  public ObjectError(String objectName, String defaultMessage) { super(""); }
+
+  public ObjectError(
+      String objectName,
+      @Nullable String[] codes,
+      @Nullable Object[] arguments,
+      @Nullable String defaultMessage) { super(""); }
+
+  public String getObjectName() {
+    return null;
+  }
+
+  public void wrap(Object source) {}
+
+  public <T> T unwrap(Class<T> sourceType) {
+    return null;
+  }
+
+  public boolean contains(Class<?> sourceType) {
+    return false;
+  }
+
+  @Override
+  public boolean equals(@Nullable Object other) {
+    return false;
+  }
+
+  @Override
+  public int hashCode() {
+    return 0;
+  }
+
+  @Override
+  public String toString() {
+    return "";
+  }
+}