@Nullable
  private InstructionImpl reduceAllNegationsIntoInstruction(GroovyPsiElement currentScope, List<? extends GotoInstruction> negations) {
    if (negations.size() > 1) {
      InstructionImpl instruction = addNode(new InstructionImpl(currentScope));
      for (GotoInstruction negation : negations) {
        addEdge(negation, instruction);
      }
      return instruction;
    }
    else if (negations.size() == 1) {
      GotoInstruction instruction = negations.get(0);
      myHead = instruction;
      return instruction;
    }
    return null;
  }
@Nullable
  private InstructionImpl reduceAllNegationsIntoInstruction(GroovyPsiElement currentScope, List<? extends GotoInstruction> negations)