def METHOD_NAME():
    """load bundled libzmq if there is one"""
    import platform
    dlopen = hasattr(sys, 'getdlopenflags')  # unix-only
    # RTLD flags are added to os in Python 3
    # get values from os because ctypes values are WRONG on pypy
    PYPY = platform.python_implementation().lower() == 'pypy'
    if dlopen:
        import ctypes
        dlflags = sys.getdlopenflags()
        # set RTLD_GLOBAL, unset RTLD_LOCAL
        flags = ctypes.RTLD_GLOBAL | dlflags
        # ctypes.RTLD_LOCAL is 0 on pypy, which is *wrong*
        flags &= ~getattr(os, 'RTLD_LOCAL', 4)
        # pypy on darwin needs RTLD_LAZY for some reason
        if PYPY and sys.platform == 'darwin':
            flags |= getattr(os, 'RTLD_LAZY', 1)
            flags &= ~getattr(os, 'RTLD_NOW', 2)
        sys.setdlopenflags(flags)
    try:
        from . import libzmq
    except ImportError:
        # raise on failure to load if libzmq is present
        from importlib.util import find_spec
        if find_spec(".libzmq", "zmq"):
            # found libzmq, but failed to load it!
            # raise instead of silently moving on
            raise
    else:
        # store libzmq as zmq._libzmq for backward-compat
        globals()['_libzmq'] = libzmq
        if PYPY:
            # should already have been imported above, so reimporting is as cheap as checking
            import ctypes
            # some versions of pypy (5.3 < ? < 5.8) needs explicit CDLL load for some reason,
            # otherwise symbols won't be globally available
            # do this unconditionally because it should be harmless (?)
            ctypes.CDLL(libzmq.__file__, ctypes.RTLD_GLOBAL)
    finally:
        if dlopen:
            sys.setdlopenflags(dlflags)