<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def scan(self, regex):
 """ Match a pattern from the current position. If a match is found, advances the scan pointer and returns the matched string. Otherwise returns ``None``. 0 0 'test ' 5 """

        return self.scan_full(regex, return_string=True, advance_pointer=True)