code: void validate() {
  		if (isVisible()) {
  			String error = validateInput();
  			setErrorMessage(error);
  			setPageComplete(error == null);
  		}
  	}
docs: Validates the contents of this wizard page.
  <p>
  Feedback about the validation is given to the user by displaying error
  messages or informative messages on the wizard page. Depending on the
  provided user input, the wizard page is marked as being complete or not.
  <p>
  If some error or missing input is detected in the user input, an error
  message or informative message, respectively, is displayed to the user.
  If the user input is complete and correct, the wizard page is marked as
  begin complete to allow the wizard to proceed. To that end, the following
  conditions must be met:
  <ul>
  <li>The user must have provided a valid group ID.</li>
  <li>The user must have provided a valid artifact ID.</li>
  <li>The user must have provided a version for the artifact.</li>
  </ul>
  </p>
  
  @see org.eclipse.jface.dialogs.DialogPage#setMessage(java.lang.String)
  @see org.eclipse.jface.wizard.WizardPage#setErrorMessage(java.lang.String)
  @see org.eclipse.jface.wizard.WizardPage#setPageComplete(boolean)