input: Write a function to modify the provided code such that it raises a `TypeError` if the input value is not an integer. The original function calculates the square root of the input.
  
  def square_root(x):
      if not isinstance(x, int):
          raise TypeError('Input must be an integer')
      return x**0.5
  
  assert square_root(4)==2.0
  assert square_root(16)==4.0
  try:
      square_root('4')
      assert False
  except TypeError:
      assert True
  try:
      square_root(4.0)
      assert False
  except TypeError:
      assert True
output: def square_root(x):
      if not isinstance(x, int):
          raise TypeError('Input must be an integer')
      return x**0.5