<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def copy(self):
 """Returns a copy of the version."""

        other = Version(None)
        other.tokens = self.tokens[:]
        other.seps = self.seps[:]
        return other