toString method
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";
}