pub trait BaseParseImpl: BaseParseImplExt + ElementImpl {
    fn start(&self, element: &Self::Type) -> Result<(), ErrorMessage> { ... }
    fn stop(&self, element: &Self::Type) -> Result<(), ErrorMessage> { ... }
    fn set_sink_caps(
        &self, 
        element: &Self::Type, 
        caps: &Caps
    ) -> Result<(), ErrorMessage> { ... }
    fn handle_frame<'a>(
        &'a self, 
        element: &Self::Type, 
        frame: BaseParseFrame<'_>
    ) -> Result<(FlowSuccess, u32), FlowError> { ... }
    fn convert<V: Into<GenericFormattedValue>>(
        &self, 
        element: &Self::Type, 
        src_val: V, 
        dest_format: Format
    ) -> Option<GenericFormattedValue> { ... }
}