toString method
Returns a description of the format exception.
The description always contains the message.
If source is present and is a string, the description will contain (at least a part of) the source. If offset is also provided, the part of the source included will contain that offset, and the offset will be marked.
If the source is a string and it contains a line break before offset, only the line containing offset will be included, and its line number will also be part of the description. Line and character offsets are 1-based.
Implementation
@override
String toString() => 'SerializationException: $message';