code: public void addCustomTag(Taglet customTag) {
          if (customTag != null) {
              String name = customTag.getName();
              if (customTags.containsKey(name)) {
                  customTags.remove(name);
              }
              customTags.put(name, customTag);
              checkTagName(name);
          }
      }
docs: Add a new <code>CustomTag</code>.  This is used to add a Taglet from within
  a Doclet.  No message is printed to indicate that the Taglet is properly
  registered because these Taglets are typically added for every execution of the
  Doclet.  We don't want to see this type of error message every time.
  @param customTag the new <code>CustomTag</code> to add.