<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def set_last_build_date(self):
 """Parses last build date and set value"""

        try:
            self.last_build_date = self.soup.find('lastbuilddate').string
        except AttributeError:
            self.last_build_date = None