tweak overloading of Base.in

Author: ablaom

src/equality.jl

@@ -158,6 +158,7 @@ Base.in(x::MLJType, itr::Set) = special_in(x, itr)
 Base.in(x::MLJType, itr::AbstractVector{<:MLJType}) = special_in(x, itr)
 Base.in(x::MLJType, itr::AbstractRange{<:MLJType}) = special_in(x, itr)
 Base.in(x::MLJType, itr::Tuple) = special_in(x, itr)
+Base.in(x::MLJType, itr::Tuple{(Any for _ in 1:32)..., Vararg{Any}}) = special_in(x, itr)
 
 # A version of `in` that actually uses `==`: