code: public <FORM> HtmlResponse useForm(Class<FORM> formType, PushedFormOpCall<FORM> opLambda) {
          assertArgumentNotNull("formType", formType);
          assertArgumentNotNull("opLambda", opLambda);
          this.pushedFormInfo = createPushedFormInfo(formType, createPushedFormOption(opLambda));
          return this;
      }
docs: Set up the HTML response as using action form with internal initial value. <br>
  And you can use the action form in your HTML template.
  <pre>
  <span style="color: #3F7E5E">// case of internal initial value</span>
  &#064;Execute
  <span style="color: #70226C">public</span> HtmlResponse index() {
  <span style="color: #70226C">return</span> asHtml(<span style="color: #0000C0">path_Sea_SeaJsp</span>).<span style="color: #CC4747">useForm</span>(SeaForm.<span style="color: #70226C">class</span>, op <span style="color: #90226C; font-weight: bold"><span style="font-size: 120%">-</span>&gt;</span> op.<span style="color: #994747">setup</span>(form <span style="color: #90226C; font-weight: bold"><span style="font-size: 120%">-</span>&gt;</span> ...));
  }
  </pre>
  @param formType The type of action form. (NotNull)
  @param opLambda The callback for option of the form, provides new-created form instance, so you can setup it. (NotNull)
  @return this. (NotNull)