input: Write a python function to round off a number to the nearest integer.
  assert round_off(2.3) == 2
  assert round_off(2.5) == 3
  assert round_off(3.7) == 4
  assert round_off(4.4) == 4
  assert round_off(5.5) == 6
output: def round_off(number):
      return round(number)