@Override
        protected void processInstruction(final @NotNull Set<? super PsiElement> res, final @NotNull Instruction instruction, int index) {
          if (instruction instanceof ReadVariableInstruction) {
            ReadVariableInstruction instructionR = (ReadVariableInstruction)instruction;
            if (psiManager.areElementsEquivalent(instructionR.variable, def)) {

              final PsiElement element = flow.getElement(index);
              element.accept(new JavaRecursiveElementWalkingVisitor() {
                @Override
                public void visitReferenceExpression(@NotNull PsiReferenceExpression ref) {
                  if (ref.isReferenceTo(def)) {
                    res.add(ref);
                  }
                }
              });
            }
          }
        }
@Override
        protected void processInstruction(final @NotNull Set<? super PsiElement> res, final @NotNull Instruction instruction, int index)