Named arguments aren't fully supported

[DanielRuthardt]

bashp/libs/file/copy

Line 31 in 3f94c35

local source=${1:-${source:?must be set}}

bashp/libs/file/copy

Line 32 in 3f94c35

local destination=${2:-${destination:?must be set}}

bashp/libs/file/copy

Line 33 in 3f94c35

shift 2

shift 2 needs to be smart and shift 0-2 arguments, depending on how the function was called.