Can anyone answer about this question?

Why use of Integer type makes program slower.

If you run the below code, you might see it takes about 0.13 second to use the data of type UnitRange{Integer}.

```
repetition = 30
mat = rand(1000,1000)
unitrange_integer = UnitRange{Integer}(1:250)
unitrange = UnitRange(1:250)
times_unitrange_integer = Vector{Float64}()
for i=1:repetition
push!(times_unitrange_integer, @elapsed mat[unitrange_integer, unitrange_integer])
end
times_unitrange = Vector{Float64}()
for i=1:repetition
push!(times_unitrange, @elapsed mat[unitrange,unitrange])
end
times_hardcoding = Vector{Float64}()
for i=1:repetition
push!(times_hardcoding, @elapsed mat[1:250,1:250])
end
println(median(times_unitrange_integer),"\t", median(times_unitrange), "\t", median(times_hardcoding))
```