code: public void goToStepId(int id) {
          for (int i = 0; i < getWidgetCount(); i++) {
              Widget w = getWidget(i);
              if (w instanceof MaterialStep) {
                  MaterialStep materialStep = (MaterialStep) w;
                  boolean active = materialStep.getStep() == id;
                  materialStep.setActive(active);
                  if (active) {
                      setCurrentStepIndex(i);
                  }
              }
          }
      }
docs: Go to the step with the specified step id.
  
  @see MaterialStep#getStep()