code: public static XMethod createXMethod(PreorderVisitor visitor) {
          JavaClass javaClass = visitor.getThisClass();
          Method method = visitor.getMethod();
          XMethod m = createXMethod(javaClass, method);
          return m;
      }
docs: Create an XMethod object from the method currently being visited by the
  given PreorderVisitor.
  
  @param visitor
  the PreorderVisitor
  @return the XMethod representing the method currently being visited