def parse_operand(self, buf):
buf = iter(buf)<EOL>try:<EOL><INDENT>operand = <NUM_LIT:0><EOL>for _ in range(self.operand_size):<EOL><INDENT>operand <<= <NUM_LIT:8><EOL>operand |= next(buf)<EOL><DEDENT>self._operand = operand<EOL><DEDENT>except StopIteration:<EOL><INDENT>raise ParseError("<STR_LIT>")<EOL><DEDENT>
Parses an operand from buf

            :param buf: a buffer
            :type buf: iterator/generator/string