code: def p_define_service(p):
      
      if len(p) == 7:
          body = p[4] + p[5]
      else:
          body = p[4]
      p[0] = DefineService(p[2], body)
docs: define_service : SERVICE IDENTIFIER OPEN_CURLY_BRACKET settings operation_list CLOSE_CURLY_BRACKET
                     | SERVICE IDENTIFIER OPEN_CURLY_BRACKET operation_list CLOSE_CURLY_BRACKET