pub unsafe extern "C" fn g_signal_newv(
    signal_name: *const i8,
    itype: usize,
    signal_flags: u32,
    class_closure: *mut GClosure,
    accumulator: Option<unsafe extern "C" fn(_: *mut GSignalInvocationHint, _: *mut GValue, _: *const GValue, _: *mut c_void) -> i32>,
    accu_data: *mut c_void,
    c_marshaller: Option<unsafe extern "C" fn(_: *mut GClosure, _: *mut GValue, _: u32, _: *const GValue, _: *mut c_void, _: *mut c_void)>,
    return_type: usize,
    n_params: u32,
    param_types: *mut usize
) -> u32