@abc.abstractmethod<EOL><INDENT>def get_maximum_heading_values(self, heading_type):<DEDENT>
return<EOL>
Gets the maximum heading values given supported heading type.

        :param heading_type: a heading Type
        :type heading_type: ``osid.type.Type``
        :return: the maximum heading values
        :rtype: ``decimal``
        :raise: ``IllegalState`` -- syntax is not a ``HEADING``
        :raise: ``NullArgument`` -- ``heading_type`` is ``null``
        :raise: ``Unsupported`` -- ``supports_heading_type(heading_type)`` is ``false``

        *compliance: mandatory -- This method must be implemented.*