toString method
A string representation of this object.
Some classes have a default textual representation,
often paired with a static parse function (like int.parse).
These classes will provide the textual representation as
their string representation.
Other classes have no meaningful textual representation
that a program will care about.
Such classes will typically override toString to provide
useful information when inspecting the object,
mainly for debugging or logging.
Implementation
@override
String toString() {
  const prefix = "Instance of '";
  final result = super.toString();
  return result.startsWith(prefix)
      ? result.substring(prefix.length).replaceFirst("'", '')
      : result;
}