toString method Null safety
Returns a string which represents the underlying type.
The string is only intended for providing information to a reader while debugging. There is no guaranteed format, the string value returned for a Type instances is entirely implementation dependent.
The string should be consistent, so a
Type object for the same type
returns the same string throughout a program execution.
The string may or may not contain parts corresponding to the
source name of declaration of the type, if the type has a source name
at all (some types reachable through
dart:mirrors may not).