# toString method

String toString ()

Returns a string representation of this object.

## Implementation

    String toString() {
      String nameString = "";
      if (name != null) {
        nameString = " ($name)";
      }
      var message = (this.message == null) ? "" : ": ${this.message}";
      String prefix = "$_errorName$nameString$message";
      if (!_hasValue) return prefix;
      // If we know the invalid value, we can try to describe the problem.
      String explanation = _errorExplanation;
      String errorValue = Error.safeToString(invalidValue);
      return "$prefix$explanation: $errorValue";
    }