def start(builtins=False, profile_threads=True):
<EOL>_vendorized_yappi.yappi.set_context_id_callback(<EOL>lambda: greenlet and id(greenlet.getcurrent()) or <NUM_LIT:0>)<EOL>_vendorized_yappi.yappi.set_context_name_callback(<EOL>lambda: greenlet and greenlet.getcurrent().__class__.__name__ or '<STR_LIT>')<EOL>_vendorized_yappi.yappi.start(builtins, profile_threads)<EOL>
Starts profiling all threads and all greenlets.

    This function can be called from any thread at any time.
    Resumes profiling if stop() was called previously.

    * `builtins`: Profile builtin functions used by standart Python modules.
    * `profile_threads`: Profile all threads if ``True``, else profile only the
      calling thread.