Function tp_new_impl 

pub unsafe fn tp_new_impl<'py, InitializerT, ClassT>(
    py: Python<'py>,
    initializer: InitializerT,
    cls: *mut PyTypeObject,
) -> PyResult<*mut PyObject>
where
    InitializerT: PyClassInit<'py, ClassT>,

SAFETY

• cls must be the type object for ClassT (or a subclass)