<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_role_types(self):
 """ Get a list of role types in a service. @return: A list of role types (strings) """

    resp = self._get_resource_root().get(self._path() + '/roleTypes')
    return resp[ApiList.LIST_KEY]