public MustacheEngineBuilder registerCallback(
            EngineBuiltCallback callback) {
        checkArgumentNotNull(callback);
        checkNotBuilt();
        this.engineReadyCallbacks.add(callback);
        return this;
    }
public MustacheEngineBuilder registerCallback(
            EngineBuiltCallback callback) {
        checkArgumentNotNull(callback);
        checkNotBuilt();
        this.engineReadyCallbacks.add(callback);
        return this;
    }
public MustacheEngineBuilder registerCallback ( EngineBuiltCallback callback ) { checkArgumentNotNull ( callback ) ; checkNotBuilt ( ) ; this . engineReadyCallbacks . add ( callback ) ; return this ; }
Callback is useful to configure a component instantiated before the
engine is built.

@param callback
@return self
Callback is useful to configure a component instantiated before the engine is built .