Singleton to start from

eth-amp-analytics-wp.php

+<?php
+/*
+Plugin Name: Google Analytics for AMP
+Plugin URI: https://ethitter.com/plugins/
+Description: Enable Google Analytics support for Automattic's AMP plugin
+Author: Erick Hitter
+Version: 0.1
+Author URI: https://ethitter.com/
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+class ETH_AMP_Analytics_WP {
+	/**
+	 * Singleton
+	 */
+	private static $instance = null;
+
+	/**
+	 * Instantiate singleton
+	 */
+	public static function get_instance() {
+		if ( ! is_a( self::$instance, __CLASS__ ) ) {
+			self::$instance = new self;
+		}
+
+		return self::$instance;
+	}
+
+	/**
+	 * Register actions and filters
+	 *
+	 * @return null
+	 */
+	private function __construct() {
+		//
+	}
+}
+
+ETH_AMP_Analytics_WP::get_instance();
\ No newline at end of file