@Nullable
  private static DfaRelation getBinaryExpressionRelation(MemoryStateChange change, PsiBinaryExpression binOp) {
    PsiExpression lOperand = binOp.getLOperand();
    PsiExpression rOperand = binOp.getROperand();
    MemoryStateChange leftPos = change.findExpressionPush(lOperand);
    MemoryStateChange rightPos = change.findExpressionPush(rOperand);
    if (leftPos != null && rightPos != null) {
      DfaValue leftValue = leftPos.myTopOfStack;
      DfaValue rightValue = rightPos.myTopOfStack;
      RelationType type = DfaPsiUtil.getRelationByToken(binOp.getOperationTokenType());
      if (type != null) {
        return DfaRelation.createRelation(leftValue, type, rightValue);
      }
    }
    return null;
  }
@Nullable
  private static DfaRelation getBinaryExpressionRelation(MemoryStateChange change, PsiBinaryExpression binOp)