Potentially problematic method definition

https://github.com/JuliaMath/Infinities.jl/blob/489b68b594f436f6b068c222939c9f537d20b928/src/cardinality.jl#L192

Aqua flags this method as potential type-piracy (see https://github.com/JuliaTesting/Aqua.jl/issues/173). I think this is fine, and the flag is a false positive, but why do we need this method? Is a real infinity used as an array size or index, as opposed to the integer `ℵ₀`?