Rotation of the array in Ruby

ruby_rotating_array.rb

# An array A consisting of N integers is given. 
# Rotation of the array means that each element is shifted right by one index, 
# and the last element of the array is moved to the first place. 
# For example, the rotation of array A = [3, 8, 9, 7, 6] is [6, 3, 8, 9, 7] 
# (elements are shifted right by one index and 6 is moved to the first place).

def solution(a, k)
  # write your code in Ruby 2.2
  k.times do
    a = [a.last] + a.shift(a.size-1)
  end
  return a
end