<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_xy_catnames(self):
 """ Return a string with the names of input_xy catalog names """

        catstr = self.name+'  '
        if 'input_xy' in self.catalog_names:
            for xycat in self.catalog_names['input_xy']:
                catstr += '  '+xycat
        return catstr + '\n'