<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _structure_unicode(self, obj, cl):
 """Just call ``cl`` with the given ``obj``"""

        if not isinstance(obj, (bytes, unicode)):
            return cl(str(obj))
        else:
            return obj