@Override
                protected void transfer(Pipe pipe, Input input, Output output) throws IOException
                {
                    for (int number = input.readFieldNumber(entrySchema);;
                    number = input.readFieldNumber(entrySchema))
                    {
                        switch (number)
                        {
                            case 0:
                                return;
                            case 1:
                                transferKey(pipe, input, output, 1, false);
                                break;
                            case 2:
                                transferValue(pipe, input, output, 2, false);
                                break;
                            default:
                                throw new ProtostuffException("The map was incorrectly " +
                                        "serialized.");
                        }
                    }
                }
The pipe schema of the {@link Map}.
protostuff-collectionschema/src/main/java/io/protostuff/MapSchema.java