code: def deprecated(will_be=None, on_version=None, name=None):
      
      def outer_function(function):
          if name is None:
              _name = function.__name__
          else:
              _name = name
          warning_msg = '"%s" is deprecated.' % _name
          if will_be is not None and on_version is not None:
              warning_msg += " It will be %s on version %s" % (
                  will_be,
                  '.'.join(map(str, on_version)))
  
          @wraps(function)
          def inner_function(*args, **kwargs):
              warnings.warn(warning_msg,
                            category=DeprecationWarning,
                            stacklevel=2)
              return function(*args, **kwargs)
  
          return inner_function
  
      return outer_function
docs: Function decorator that warns about deprecation upon function invocation.
      :param will_be: str representing the target action on the deprecated function
      :param on_version: tuple representing a SW version
      :param name: name of the entity to be deprecated (useful when decorating
      __init__ methods so you can specify the deprecated class name)
      :return: callable