WP_Widget_Media_Audio::render_media

	public function render_media( $instance ) {
		$instance   = array_merge( wp_list_pluck( $this->get_instance_schema(), 'default' ), $instance );
		$attachment = null;

		if ( $this->is_attachment_with_mime_type( $instance['attachment_id'], $this->widget_options['mime_type'] ) ) {
			$attachment = get_post( $instance['attachment_id'] );
		}

		if ( $attachment ) {
			$src = wp_get_attachment_url( $attachment->ID );
		} else {
			$src = $instance['url'];
		}

		echo wp_audio_shortcode(
			array_merge(
				$instance,
				compact( 'src' )
			)
		);
	}