input: Write a function to modify the given Python code so that it raises an exception if the input value is not an integer. The function should be named `square_root` and should return the square root of the input if it is an integer. If the input is not an integer, it should raise a `TypeError` with the message 'Input must be an integer'.
  
  assert square_root(4)==2.0
  assert square_root(9)==3.0
  try:
      square_root("4")
  except TypeError:
      pass
  else:
      assert False
  try:
      square_root(4.5)
  except TypeError:
      pass
  else:
      assert False
  assert square_root(0)==0.0
  assert square_root(1)==1.0
output: def square_root(value):
      if not isinstance(value, int):
          raise TypeError('Input must be an integer')
      return value ** 0.5