pub unsafe extern "C" fn object_class_property_add_str(
    klass: *mut ObjectClass,
    name: *const c_char,
    get: Option<unsafe extern "C" fn(arg1: *mut Object, arg2: *mut *mut Error) -> *mut c_char>,
    set: Option<unsafe extern "C" fn(arg1: *mut Object, arg2: *const c_char, arg3: *mut *mut Error)>,
    errp: *mut *mut Error
)