<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def delete_database_user(self, username):
 """Delete database user."""

        url = "db/{0}/users/{1}".format(self._database, username)

        self.request(
            url=url,
            method='DELETE',
            expected_response_code=200
        )

        return True