public static function get_ajax_payload( $handle = '' ) {
		$payload = null;

		if ( ! empty( $_POST['payload'] ) ) {
			$payload = $_POST['payload']; // Could be either a string or an array.
		}

		/**
		 * Filter the Ajax payload.
		 *
		 * @param mixed  $payload The ajax payload.
		 * @param string $handle  The current handler's handle.
		 */
		$payload = apply_filters( 'WP_Ajax_Helper\ajax_payload', $payload, $handle );

		return $payload;
	}