Reading Binary data back in py3 breaks

[shashank88]

data = lib.read('gen:6447069510335728072', as_of='snap:6447069510335728072:fe9e74b04cee6a12').data

I get a bson.binary.Binary on 27-3 and TypeError: data must be an instance of bytes on 36-1. Similar items do read fine on 36-1, returning a bytes

My guess is that this is happening due to the type of what's being stored inside the Binary. eg. a str when loaded back in py3 breaks as the bson.binary.Binary constructor. eg:

In [1]: import bson, pickle

In [2]: s = bson.binary.Binary('a')
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-2-b90cb3c1049b> in <module>()
----> 1 s = bson.binary.Binary('a')

/users/is/ahlpypi/medusa_egg_cache/36-1/p/pymongo-3.6.0-py3.6-linux-x86_64.egg/bson/binary.py in __new__(cls, data, subtype)
    145     def __new__(cls, data, subtype=BINARY_SUBTYPE):
    146         if not isinstance(data, bytes):
--> 147             raise TypeError("data must be an instance of bytes")
    148         if not isinstance(subtype, int):
    149             raise TypeError("subtype must be an instance of int")

TypeError: data must be an instance of bytes

In [3]: s = bson.binary.Binary(b'a')

In [4]: 'a'
Out[4]: 'a'