10     """Flags a method as deprecated. 
   12         instructions: A human-friendly string of instructions, such 
   13             as: 'Please migrate to add_proxy() ASAP.' 
   17         """This is a decorator which can be used to mark functions 
   18         as deprecated. It will result in a warning being emitted 
   19         when the function is used.""" 
   21         @functools.wraps(func)
 
   22         def wrapper(*args, **kwargs):
 
   23             message = f
"Call to deprecated function {func.__name__}. {instructions}" 
   25             warnings.warn(message, category=DeprecatedWarning, stacklevel=2)
 
   27             return func(*args, **kwargs)
 
   29         instructions_doc = 
"Deprecated: " + instructions
 
   30         if wrapper.__doc__ 
is None:
 
   31             wrapper.__doc__ = instructions_doc
 
   33             wrapper.__doc__ = wrapper.__doc__.rstrip() + 
"\n\n" + instructions_doc