@Override
    public boolean isStringJoin(PsiPolyadicExpression expression, List<? extends PsiExpression> diff) {
      if (!myMapToString.isEmpty()) return false;
      PsiExpression[] operands = getOperands(expression);
      return operands[0] == diff.get(0);
    }
@Override
    public boolean isStringJoin(PsiPolyadicExpression expression, List<? extends PsiExpression> diff)