:meth:`.WBlockPadding.pad` method implementation

def pad(self, data, block_size):
		""" :meth:`.WBlockPadding.pad` method implementation
		"""
		padding_symbol = self.padding_symbol()

		blocks_count = (len(data) // block_size)
		if (len(data) % block_size) != 0:
			blocks_count += 1

		total_length = blocks_count * block_size
		return self._fill(data, total_length, padding_symbol)