Bitpay\Util\Error::handler PHP Method

    public final function handler($type = 'error', $action = 'restore', $callable_handler = false, $error_types = null)
    {
        if (empty($error_types)) {
            $error_types = E_ALL | E_STRICT;
        }
        switch (strtolower($type)) {
            case 'error':
                switch (strtolower($action)) {
                    case 'restore':
                        return restore_error_handler();
                        break;
                    case 'set':
                        return set_error_handler($callable_handler, $error_types);
                        break;
                    default:
                        return false;
                }
                break;
            case 'exception':
                switch (strtolower($action)) {
                    case 'restore':
                        return restore_exception_handler();
                        break;
                    case 'set':
                        return set_exception_handler($callable_handler);
                        break;
                    default:
                        return false;
                }
                break;
            default:
                return false;
        }
    }