docs: def GroupsGet(self, parameters = None, group_id = -1):
          """
              Retrieve groups from CommonSense, according to parameters, or by group id. 
              If successful, result can be obtained by a call to getResponse(), and should be a json string.
              
              @param parameters (dictionary) (optional) - Dictionary containing the parameters for the api-call.
              @param group_id (int) (optional) - Id of the group to retrieve details from.
              
              @return (boolean) - Boolean indicating whether GroupsGet was successful.
          """
          if parameters is None and group_id == -1:
              self.__error__ = "no arguments"
              return False
  
          url = ''
          if group_id is -1:
              url = '/groups.json'
          else:
              url = '/groups/{0}.json'.format(group_id)
  
          if self.__SenseApiCall__(url, 'GET', parameters = parameters):
              return True
          else:
              self.__error__ = "api call unsuccessful"
              return False