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() => '($value1, $value2, $value3, $value4, $value5, $value6, $value7, $value8, $value9, $value10, $value11, $value12, $value13, $value14, $value15, $value16, $value17, $value18, $value19, $value20)';