pub unsafe extern "C" fn gst_device_provider_class_add_metadata(
klass: *mut GstDeviceProviderClass,
key: *const c_char,
value: *const c_char,
)
pub unsafe extern "C" fn gst_device_provider_class_add_metadata(
klass: *mut GstDeviceProviderClass,
key: *const c_char,
value: *const c_char,
)