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() => "NoSuchAsEncodingErr: The Encoding key or name \"${this.candidate}\" is not exist in availables. \nAvailable keys are: " + this.recs.map<String>((EncodingTabRec r) => "\"${r.key}\"").join(", ") + "\nAvailable names are: " + this.recs.map<String>((EncodingTabRec r) => "\"${r.encoding.name}\"").join(", ") + ".";