How to leave only unique rows of array

General Usage
2

See Unique (indices) method similar to MATLAB — for example, if you have a matrix a and you want the rows corresponding to whether columns 1 and 2 are unique, you could do:

julia> a = [ "Kalinka"  "surname"
        "Kalinka"  "surname"
        "Kalinka"  "surname"
        "Kalinka"  "geographical_name"
        "Kalinka"  "geographical_name"
        "Kalinka"  "geographical_name"
        "Kalinka"  "geographical_name"
        "Kalinko"  "surname"
        "Kalinko"  "surname"
        "Kalinka"  "name"
        "Kalinka"  "name"];

julia> idx = unique(i -> (a[i,1], a[i,2]), axes(a, 1))
4-element Vector{Int64}:
  1
  4
  8
 10

julia> a[idx,:] # rows where (col1, col2) are unique
4×2 Matrix{String}:
 "Kalinka"  "surname"
 "Kalinka"  "geographical_name"
 "Kalinko"  "surname"
 "Kalinka"  "name"