CakePHP 3 App Core Configuration - require configuration to be set.

Configure.php

<?php
    /**
     * Used to get information stored in Configure. It's not
     * possible to store `null` values in Configure.
     *
     * Acts as a wrapper around Configure::read() and Configure::check().
     * The configure value fetched via get is expected to exist. 
     * In case it does not an exception will be thrown.
     *
     * Usage:
     * ```
     * Configure::get('Name'); will return all values for Name
     * Configure::get('Name.key'); will return only the value of Configure::Name[key]
     * ```
     *
     * @param string $var Variable to obtain. Use '.' to access array elements.
     * @return mixed value stored in configure.
     * @link http://book.cakephp.org/3.0/en/development/configuration.html#reading-configuration-data
     * @throws \Cake\Core\Exception\Exception if the requested configuration is not set.
     */
    public static function get($var) {
        if (static::check($var) === false) {
            throw new Exception(sprintf('Expected "%s" configuration.', $var));
        }
        return static::read($var);
    }