private void buildPathVariables(
      ExecutableElement executableElement, RestDocumentation.Resource.Method doc) {
    RestDocumentation.Resource.Method.UrlFields subs = doc.getUrlSubstitutions();

    for (VariableElement var : executableElement.getParameters()) {
      PathVariable pathVar = var.getAnnotation(PathVariable.class);
      if (pathVar != null) {
        addUrlField(subs, var, pathVar.value());
      }
    }
  }
  private void buildUrlParameters(
      ExecutableElement executableElement, RestDocumentation.Resource.Method doc) {
    RestDocumentation.Resource.Method.UrlFields subs = doc.getUrlParameters();

    for (VariableElement var : executableElement.getParameters()) {
      RequestParam reqParam = var.getAnnotation(RequestParam.class);
      if (reqParam != null) {
        addUrlField(subs, var, reqParam.value());
      }
    }
  }
  private void buildRequestBodies(
      ExecutableElement executableElement, RestDocumentation.Resource.Method doc) {
    List<VariableElement> requestBodies = new ArrayList<VariableElement>();
    for (VariableElement var : executableElement.getParameters()) {
      if (var.getAnnotation(org.springframework.web.bind.annotation.RequestBody.class) != null) {
        requestBodies.add(var);
      }
    }

    if (requestBodies.size() > 1) {
      throw new IllegalStateException(
          String.format(
              "Method %s in class %s has multiple @RequestBody params",
              executableElement.getSimpleName(), executableElement.getEnclosingElement()));
    }

    if (requestBodies.size() == 1) {
      buildRequestBody(requestBodies.get(0), doc);
    }
  }