/**
     * Creates the HTML for the Assign to Use Field
     * @param int $assign Existing field data
     */
    protected function create_assign_field($assign = NULL)
    {
        if (CTDL_Loader::$settings['list_view'] != 0 && (CTDL_Loader::$settings['assign'] == 0 && current_user_can(CTDL_Loader::$settings['assign_capability']))) {
            $this->form .= '<tr>
		  		<th scope="row"><label for="cleverness_todo_assign">' . apply_filters('ctdl_assign', esc_html__('Assign To', 'cleverness-to-do-list')) . '</label></th>
		  		<td>
		  			<select name="cleverness_todo_assign[]" id="cleverness_todo_assign" multiple="multiple" style="width: 220px;"><option></option>';
            if (CTDL_Loader::$settings['user_roles'] == '') {
                $roles = array('contributor', 'author', 'editor', 'administrator');
            } else {
                $roles = explode(", ", CTDL_Loader::$settings['user_roles']);
            }
            foreach ($roles as $role) {
                $role_users = CTDL_Lib::get_users($role);
                foreach ($role_users as $role_user) {
                    $selected = '';
                    if (is_array($assign)) {
                        if (isset($assign) && in_array($role_user->ID, $assign)) {
                            $selected = ' selected="selected"';
                        }
                    } else {
                        if (isset($assign) && $assign == $role_user->ID) {
                            $selected = ' selected="selected"';
                        }
                    }
                    $this->form .= sprintf('<option value="%d"%s>%s</option>', $role_user->ID, $selected, $role_user->display_name);
                }
            }
            $this->form .= '</select>';
            $this->form .= '</td></tr>';
        }
    }