Function fastcall_cfunction_with_keywords 

pub unsafe extern "C" fn fastcall_cfunction_with_keywords<Meth: MethodDef<Func>>(
    slf: *mut PyObject,
    args: *const *mut PyObject,
    nargs: Py_ssize_t,
    kwnames: *mut PyObject,
) -> *mut PyObject

External symbol called by Python, which calls the provided Rust function.

The Rust function is supplied via the generic parameter Meth.

Safety

The interpreter must be attached