def convert_endianness(array: bytes):
	"""
	Switch between big-endian order and little-endian order. 
	Bitcoin stores bytes in little-endian byte order but we human beings are 
	more comfortable with big-endian one. Therefore, we convert the endianness
	before showing values to users.
	Note that bytes objects are immutable
	"""
	assert isinstance(array, bytes)
	return array[::-1]