protoc --encode=userdefined.proto what is the equivalent function and how to use

[thomas d]

when using the command line compiler directive protoc --encode= to encode the user defined proto that you have what is the equivalent function call of this encoding. I have been looking in encoder.py and seen functions like:

def MessageEncoder(field_number, is_repeated, is_packed)

but not sure how to use it and if it is the same encoding being used in the compiler flag

[thomas d]

forgot to include this is with respect to the python API for protobuf3