code: public static ErrorManager get() {
  		if (ErrorManager.instance == null) {
  			ErrorManager.instance = GWT.create(ErrorManager.class);
  		}
  		return ErrorManager.instance;
  	}
docs: Get the singleton.
  <p>
  The singleton is created thanks to GWT.create(ErrorManager.class). So you can use your own
  implementation by overring it in your .gwt.xml
  </p>
  
  <pre>
  &lt;replace-with class="{your instance}"&gt;
  &lt;when-type-is class="fr.putnami.pwt.core.error.client.ErrorManager"&gt;
  &lt;/replace-with&gt;
  </pre>
  
  @return the error manager