import java
import semmle.code.java.dataflow.DataFlow

module Config implements DataFlow::ConfigSig {
  predicate isSource(DataFlow::Node n) {
    n.asExpr().(ClassInstanceExpr).getType().(RefType).getASupertype*().hasName("Source")
  }

  predicate isSink(DataFlow::Node n) { n.asExpr().(Argument).getCall().getCallee().hasName("sink") }
}

module Flow = DataFlow::Global<Config>;

from DataFlow::Node src, DataFlow::Node sink
where Flow::flow(src, sink)
select src, sink