wp-notices.php
public function register_notice( $id, $type, $content, $args = array() ) {
		if ( is_null( self::$instance->notices ) ) {
			self::$instance->notices = array();
		}

		$id      = self::$instance->get_id( $id );
		$type    = in_array( $t = sanitize_text_field( $type ), self::$instance->get_types() ) ? $t : 'updated';
		$content = wp_kses_post( $content );
		$args    = wp_parse_args( $args, self::$instance->default_args() );

		$notice = array(
			'type'    => $type,
			'content' => $content,
		);

		$notice                         = array_merge( $notice, $args );
		self::$instance->notices[ $id ] = $notice;

		return true;
	}
public function register_notice( $id, $type, $content, $args = array() ) {
		if ( is_null( self::$instance->notices ) ) {
			self::$instance->notices = array();
		}

		$id      = self::$instance->get_id( $id );
		$type    = in_array( $t = sanitize_text_field( $type ), self::$instance->get_types() ) ? $t : 'updated';
		$content = wp_kses_post( $content );
		$args    = wp_parse_args( $args, self::$instance->default_args() );

		$notice = array(
			'type'    => $type,
			'content' => $content,
		);

		$notice                         = array_merge( $notice, $args );
		self::$instance->notices[ $id ] = $notice;

		return true;
	}
Register a notice.

@param string $id
@param string $type
@param string $content
@param array $args
@return void