code: def system_methodSignature(self, method_name: str)->str:
          
          method = None
          if method_name in self.funcs:
              method = self.funcs[method_name]
          elif self.instance is not None:
              try:
                  method = resolve_dotted_attribute(
                      self.instance,
                      method_name,
                      self.allow_dotted_names
                  )
              except AttributeError:
                  pass
          if method is None:
              return ""
          else:
              return str(inspect.signature(method))
docs: 获取函数的签名.
  
          system.methodSignature('add') => [double, int, int]
  
          Parameters:
              method_name (str): - 要查看的函数名
  
          Returns:
              (str): - 签名文本