Keyword Argument


    def foo(a, b: 42, **keys)
       p [a,b,keys]
    end
    foo(1)             # => [1,42,{}]
    foo(2, b: 5)       # => [2,5,{}]
    foo(3, b: 4, c: 6) # => [3,4,{:c=>6}]