why is "shift" a number?

[emnpiex]

i believe this is a typo. this should be a boolean. it is described as being 'if' something is the case so making it a number does not make sense.

i will create a pull request to fix this but base this on #57 as there are a number of changes that would lead to conflict.

[emnpiex]

this issue should be closed if i am wrong about what "shift" is or if #59 is merged. if i am wrong about what "shift" is, i recommend making a new issue to clarify its wording.