title: Best practice to show validation errors on MVP pattern
body: <p>I have a Presenter that is used for user registration and I need to implement validation errors on it, what I've done is I created a method for each validation error, like <code>UserCannotBeEmpty()</code>, <code>InvalidEmailAddress()</code>, <code>UserAlreadyExists()</code> and so on...</p>
  
  <p>It is ok for just a few fields, but it just doesn't look good if I have a lot of fields, I would have to create a lot of methods for that...</p>
  
  <p>What't the best way to do this?</p>
  
  <p>thanks!</p>