PHP client library for Gravatar

Gravatar.php

<?php
    /*-----------------------------------------------------------------------------
     * PHP client library for Gravatar
     *
     * Author:      Gabriel Froes
     * Copyright:   (c) 2018 RW Studio
     * License:     BSD 3-Clause License
     *              See accompanying LICENSE file
     *
     * Version:     1.0
     * Updated:     -
     *-----------------------------------------------------------------------------
     */

    class gravatar {
        private $_version   = '1.0';
        private $_url       = 'https://www.gravatar.com/avatar/';
        private $_size      = 40;
        private $_default;

        public function __construct($params) {
            $this->_default = $params['default'];
            $this->_size    = $params['size'];
        }

        public function version() {
            return $this->_version;
        }

        // Return gravatar image src
        public function get_gravatar($email) {
            $img = $this->_url . md5( strtolower( trim( $email ) ) ) . "?d=" . urlencode( $this->_default ) . "&s=" . $this->_size;
            return $img;
        }
    }
?>