public static function load()
 {
     if (!class_exists('GFForms') || !class_exists('GFAddOn')) {
         return;
     }
     if (!method_exists('GFForms', 'include_feed_addon_framework')) {
         return;
     }
     GFForms::include_feed_addon_framework();
     require_once GFELOQUA_PATH . '/api/class.eloqua.api.php';
     require_once GFELOQUA_PATH . '/includes/helpers.php';
     require_once GFELOQUA_PATH . 'gfeloqua.class.php';
     GFAddOn::register('GFEloqua');
 }
<?php

GFForms::include_feed_addon_framework();
class GFZohoCRM extends GFFeedAddOn
{
    protected $_version = GF_ZOHOCRM_VERSION;
    protected $_min_gravityforms_version = '1.9.14.26';
    protected $_slug = 'gravityformszohocrm';
    protected $_path = 'gravityformszohocrm/zohocrm.php';
    protected $_full_path = __FILE__;
    protected $_url = 'http://www.gravityforms.com';
    protected $_title = 'Gravity Forms Zoho CRM Add-On';
    protected $_short_title = 'Zoho CRM';
    protected $_enable_rg_autoupgrade = true;
    protected $api = null;
    protected $fields_transient_name = 'gform_zohocrm_fields';
    private static $_instance = null;
    /* Permissions */
    protected $_capabilities_settings_page = 'gravityforms_zohocrm';
    protected $_capabilities_form_settings = 'gravityforms_zohocrm';
    protected $_capabilities_uninstall = 'gravityforms_zohocrm_uninstall';
    /* Members plugin integration */
    protected $_capabilities = array('gravityforms_zohocrm', 'gravityforms_zohocrm_uninstall');
    /**
     * Get instance of this class.
     * 
     * @access public
     * @static
     * @return GFZohoCRM
     */
    public static function get_instance()