src/ErrorMessageResolver.php
public function register($errorCode, string $message)
    {
        $this->messages = array_merge($this->messages, is_array($errorCode) ? $errorCode : [
            $errorCode => $message,
        ]);
    }
public function register($errorCode, string $message)
    {
        $this->messages = array_merge($this->messages, is_array($errorCode) ? $errorCode : [
            $errorCode => $message,
        ]);
    }
Register a message mapped to an error code.

@param  mixed  $errorCode
@param  string $message
@return void