Eth2.0-specs: Is justification_bitfield an integer or a `bytes` type?

[ChihChengLiang]

justification_bitfield is specified uint64 in the spec.

Would it make more sense to specify it as bytes type? Since the bitfield keyword indicates a byte type and it involves many bitwise operations as well.

[vbuterin]

In python it's easier to do bit operations on integers than bytes :smile:

If we go bytes, then to keep the spec being correctly executable python, we would need to make helpers for bitwise_or, bitwise_and and shift.

[ChihChengLiang]

Would it make sense to define justification_bitfield in bytes but specify the Python calculation by converting to an integer first? This has two benefits:

• The bitfield is literally bytes
• The calculation in Python is more explicitly specified in integer.

[ChihChengLiang]

A discussion shows the feel to keep it as is (integer) is stronger.