<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_system_by_name(self, name):
 """Return a system with that name or None."""


        for elem in self.systems:
            if elem.name == name:
                return elem
        return None