code: public void writeUTF8Const(String value)
      throws IOException
    {
      ConstantPool pool =  _javaClass.getConstantPool();
      Utf8Constant entry = pool.getUTF8(value);
  
      if (entry != null)
        writeShort(entry.getIndex());
      else
        throw new NullPointerException(L.l("utf8 constant {0} does not exist", value));
    }
docs: Writes a UTF8 constant.