def back(self, *fields):
        v, f = tuple(self.irange(-1, -1, fields=fields))
        if v:
            return (v[0], dict(((field, f[field][0]) for field in f)))
Return the back pair of the structure
dataset/ETHPy150Open lsbardel/python-stdnet/stdnet/apps/columnts/models.py/ColumnTS.back