def is_public_domain(self):
return self._my_map['<STR_LIT>']<EOL>
Tests if this asset is in the public domain.

        An asset is in the public domain if copyright is not applicable,
        the copyright has expired, or the copyright owner has expressly
        relinquished the copyright.

        return: (boolean) - true if this asset is in the public domain,
                false otherwise. If true, can_distribute_verbatim(),
                can_distribute_alterations() and
                can_distribute_compositions() must also be true.
        raise:  IllegalState - is_copyright_status_known() is false
        compliance: mandatory - This method must be implemented.