@Nullable
  @Override
  public PsiType getOperationType() {
    final GroovyCallReference reference = getReference();
    final GroovyResolveResult result = reference.advancedResolve();
    final PsiType operatorType = getTypeFromResult(result, reference.getArguments(), this);
    if (operatorType != null) {
      return operatorType;
    }

    final GrExpression operand = getOperand();
    if (operand == null) {
      return null;
    }
    final PsiType operandType = operand.getType();
    if (TypesUtil.isNumericType(operandType)) {
      return operandType;
    }

    return null;
  }
@Nullable
  @Override
  public PsiType getOperationType()