input: Write a function to take an array of integers and calculate the sum of squares of all numbers provided in the array. If the array is empty, return 0.
  assert sum_squares([2, 3, 4])==29
  assert sum_squares([3, 5, 7])==83
  assert sum_squares([0, 0, 0])==0
  assert sum_squares([])==0
  assert sum_squares([-1, -2, -3])==14
output: def sum_squares(arr):
      return sum(x**2 for x in arr)