def set_context_name_callback(callback):
return _yappi.set_context_name_callback(callback)<EOL>
Use a string other than the current thread's class name as the context's
name.

The callback must take no arguments and return a string. For example:

>>> import greenlet, yappi
>>> yappi.set_context_name_callback(
...     lambda: greenlet.getcurrent().__class__.__name__)