code: public static StringBuilder print(StringBuilder sb, Object bean, int level) throws IntrospectionException {
          return print(sb, Collections.newSetFromMap(new IdentityHashMap<Object, Boolean>()), bean, level);
      }
docs: Prints a bean to the StringBuilder.
  
  @param sb a StringBuilder
  @param bean an object
  @param level indentation level
  @return the original StringBuilder
  @throws IntrospectionException if bean introspection fails by {@link java.beans.Introspector Introspector}