input: Write a function to modify the given function `square_root(x)` so that it raises a `TypeError` with the message 'Input must be an integer' if the input value `x` is not an integer. If the input is an integer, the function should return the square root of `x`.
  
  assert square_root(4)==2.0
  assert square_root(0)==0.0
  assert square_root(1)==1.0
  assert square_root(9)==3.0
  try:
      square_root('4')
      assert False # This line should not be reached
  except TypeError as e:
      assert str(e)=='Input must be an integer'
  try:
      square_root(4.0)
      assert False # This line should not be reached
  except TypeError as e:
      assert str(e)=='Input must be an integer'
output: def square_root(x):
      if not isinstance(x, int):
          raise TypeError('Input must be an integer')
      return x ** 0.5