code: protected void writeClassMapping (int code, Class<?> sclass)
          throws IOException
      {
          writeShort(code);
          String cname = sclass.getName();
          if (_translations != null) {
              String tname = _translations.get(cname);
              if (tname != null) {
                  cname = tname;
              }
          }
          writeUTF(cname);
      }
docs: Writes out the mapping for a class.