Re: NvP: s.add('x') 100M times

[sschwarzer]

For the record: In Python 3, "some string" is a unicode string where the items 
are code points. The model more similar in semantics to the Nim version is the 
`bytes` type. That said, I get the same time for multiplying `b"x"` (`bytes`) 
as for `"x"` (`str`).