@classmethod
def supported_filetypes(cls):
    """ Returns a list of supported file extensions.

			# Return value

			A tuple of lowercase extensions (without the period) that generally
			indicate that the Reader subclass can handle the implied file type.
			If no file extensions is particularly indicative, then an empty
			tuple can be returned. If the absence of a file extension is
			particularly indicative, then an empty string can be present in the
			tuple.
		"""
    raise NotImplementedError
