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() {
var b = StringBuffer();
_data.forEach((k, v) {
b.write('$k: ');
b.write(v.join(','));
b.writeln();
});
return b.toString();
}