code: public static void dynamicCodeGenerate(OutputStream os, Class cls, Charset charset) throws IOException {
          dynamicCodeGenerate(os, cls, charset, getCodeGenerator(cls));
      }
docs: To generate a protobuf proxy java source code for target class.
  
  @param os to generate java source code
  @param cls target class
  @param charset charset type
  @throws IOException in case of any io relative exception.