def get_knowledge_category_id(self):
if not self.has_knowledge_category():<EOL><INDENT>raise IllegalState()<EOL><DEDENT>else:<EOL><INDENT>return Id(self._my_map['<STR_LIT>'])<EOL><DEDENT>
Gets the grade Id associated with the knowledge dimension.

        return: (osid.id.Id) - the grade Id
        raise:  IllegalState - has_knowledge_category() is false
        compliance: mandatory - This method must be implemented.