How to use the forbiddenfruit.__init__.PyMappingMethods function in forbiddenfruit

('tp_as_sequence', ctypes.POINTER(PySequenceMethods)),
    ('tp_as_mapping', ctypes.POINTER(PyMappingMethods)),
    ('tp_hash', ctypes.CFUNCTYPE(ctypes.c_int64, PyObject_p)),
    ('tp_call', ctypes.CFUNCTYPE(PyObject_p, PyObject_p, PyObject_p, PyObject_p)),
    ('tp_str', ctypes.CFUNCTYPE(PyObject_p, PyObject_p)),
    # ...
]


# redundant dict of pointee types, because ctypes doesn't allow us
# to extract the pointee type from the pointer
PyTypeObject_as_types_dict = {
    'tp_as_async': PyAsyncMethods,
    'tp_as_number': PyNumberMethods,
    'tp_as_sequence': PySequenceMethods,
    'tp_as_mapping': PyMappingMethods,
}


class SlotsProxy(PyObject):
    _fields_ = [('dict', ctypes.POINTER(PyObject))]


def patchable_builtin(klass):
    name = klass.__name__
    target = klass.__dict__

    proxy_dict = SlotsProxy.from_address(id(target))
    namespace = {}

    # This code casts `proxy_dict.dict` into a python object and
    # `from_address()` returns `py_object`

# varhead
    ('ob_base', PyObject),
    ('ob_size', Py_ssize_t),
    # declaration
    ('tp_name', ctypes.c_char_p),
    ('tp_basicsize', Py_ssize_t),
    ('tp_itemsize', Py_ssize_t),
    ('tp_dealloc', ctypes.CFUNCTYPE(None, PyObject_p)),
    ('printfunc', ctypes.CFUNCTYPE(ctypes.c_int, PyObject_p, FILE_p, ctypes.c_int)),
    ('getattrfunc', ctypes.CFUNCTYPE(PyObject_p, PyObject_p, ctypes.c_char_p)),
    ('setattrfunc', ctypes.CFUNCTYPE(ctypes.c_int, PyObject_p, ctypes.c_char_p, PyObject_p)),
    ('tp_as_async', ctypes.CFUNCTYPE(PyAsyncMethods)),
    ('tp_repr', ctypes.CFUNCTYPE(PyObject_p, PyObject_p)),
    ('tp_as_number', ctypes.POINTER(PyNumberMethods)),
    ('tp_as_sequence', ctypes.POINTER(PySequenceMethods)),
    ('tp_as_mapping', ctypes.POINTER(PyMappingMethods)),
    ('tp_hash', ctypes.CFUNCTYPE(ctypes.c_int64, PyObject_p)),
    ('tp_call', ctypes.CFUNCTYPE(PyObject_p, PyObject_p, PyObject_p, PyObject_p)),
    ('tp_str', ctypes.CFUNCTYPE(PyObject_p, PyObject_p)),
    # ...
]


# redundant dict of pointee types, because ctypes doesn't allow us
# to extract the pointee type from the pointer
PyTypeObject_as_types_dict = {
    'tp_as_async': PyAsyncMethods,
    'tp_as_number': PyNumberMethods,
    'tp_as_sequence': PySequenceMethods,
    'tp_as_mapping': PyMappingMethods,
}