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() => 'Registrant[address1=$address1, address2=$address2, city=$city, companyName=$companyName, country=$country, email=$email, fax=$fax, firstName=$firstName, lastName=$lastName, phone=$phone, state=$state, zip=$zip]';