source/php/Parser.php
public function checkIfEventExists($event_manager_id)
    {
        global $wpdb;
        $results = $wpdb->get_results(
            "SELECT post_id FROM $wpdb->postmeta WHERE meta_key = '_event_manager_id' AND meta_value = $event_manager_id LIMIT 1",
            ARRAY_A
        );
        if (!empty($results[0]['post_id'])) {
            return $results[0]['post_id'];
        } else {
            return false;
        }
    }
public function checkIfEventExists($event_manager_id)
    {
        global $wpdb;
        $results = $wpdb->get_results(
            "SELECT post_id FROM $wpdb->postmeta WHERE meta_key = '_event_manager_id' AND meta_value = $event_manager_id LIMIT 1",
            ARRAY_A
        );
        if (!empty($results[0]['post_id'])) {
            return $results[0]['post_id'];
        } else {
            return false;
        }
    }
Check if event already exist and return it's id
@param  [type] $event_manager_id [description]
@return [type]                   [description]