code: public void warning(DocImpl doc, String key, String a1) {
          if (silent)
              return;
          // suppress messages that have (probably) been covered by doclint
          if (doclint != null && doc != null && key.startsWith("tag"))
              return;
          messager.warning(doc==null ? null : doc.position(), key, a1);
      }
docs: Print warning message, increment warning count.
  
  @param key selects message from resource
  @param a1 first argument