C#: Refactoring to allow override of the flow summaries reported by a test.

csharp/ql/lib/semmle/code/csharp/dataflow/internal/FlowSummaryImpl.qll

@@ -1004,6 +1004,13 @@ module Private {
     abstract class RelevantSummarizedCallable extends SummarizedCallable {
       /** Gets the string representation of this callable used by `summary/1`. */
       abstract string getCallableCsv();
+
+      /** Holds if flow is progated between `input` and `output` */
+      predicate relevantSummary(
+        SummaryComponentStack input, SummaryComponentStack output, boolean preservesValue
+      ) {
+        this.propagatesFlow(input, output, preservesValue)
+      }
     }
 
     /** Render the kind in the format used in flow summaries. */
@@ -1023,7 +1030,7 @@ module Private {
         RelevantSummarizedCallable c, SummaryComponentStack input, SummaryComponentStack output,
         boolean preservesValue
       |
-        c.propagatesFlow(input, output, preservesValue) and
+        c.relevantSummary(input, output, preservesValue) and
         csv =
           c.getCallableCsv() + ";;" + getComponentStackCsv(input) + ";" +
             getComponentStackCsv(output) + ";" + renderKind(preservesValue)

csharp/ql/test/shared/FlowSummaries.qll

@@ -16,13 +16,14 @@ abstract class IncludeSummarizedCallable extends RelevantSummarizedCallable {
       )
   }
 
-  /* Gets a string representing, whether the declaring type is an interface. */
+  predicate isAbstractOrInterface() {
+    this.getDeclaringType() instanceof Interface or
+    this.(Modifiable).isAbstract()
+  }
+
+  /** Gets a string representing, whether the declaring type is an interface. */
   private string getCallableOverride() {
-    if
-      this.getDeclaringType() instanceof Interface or
-      this.(Modifiable).isAbstract()
-    then result = "true"
-    else result = "false"
+    if this.isAbstractOrInterface() then result = "true" else result = "false"
   }
 
   /** Gets a string representing the callable in semi-colon separated format for use in flow summaries. */