def METHOD_NAME(cls, module, name, user_data=None, signature=None):
    """
    Create a low-level callback function from an exported Cython function.
    Parameters
    ----------
    module : module
        Cython module where the exported function resides
    name : str
        Name of the exported function
    user_data : {PyCapsule, ctypes void pointer, cffi void pointer}, optional
        User data to pass on to the callback function.
    signature : str, optional
        Signature of the function. If omitted, determined from *function*.
    """
    try:
        function = module.__pyx_capi__[name]
    except AttributeError:
        raise ValueError("Given module is not a Cython module with __pyx_capi__ attribute")
    except KeyError:
        raise ValueError("No function {!r} found in __pyx_capi__ of the module".format(name))
    return cls(function, user_data, signature)