input: Write a python function to calculate the sum of squares of a list of numbers.
  assert sum_of_squares([1, 2, 3, 4]) == 30
  assert sum_of_squares([5, 6, 7]) == 110
  assert sum_of_squares([0, -1, -2]) == 5
output: def sum_of_squares(numbers):
      return sum(x**2 for x in numbers)