<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def to_geopoint(self):
 """ Returns the geoJSON compliant representation of this location :returns: a ``pyowm.utils.geo.Point`` instance """

        if self._lon is None or self._lat is None:
            return None
        return geo.Point(self._lon, self._lat)