@staticmethod
def _regr_test():
    """
>>> import tempfile, os, shutil, pandas, random
>>> from oxtie.fronts import nums
>>> from oxtie.backs import simple
>>> random.seed(123)  # Make tests repeatable
>>> backend = simple.FileBackend(root=tempfile.mkdtemp(suffix='.oxtie'))
>>> idx = [pandas.Timestamp(
...     '2017-01-%s' % str(i).zfill(2)) for i in range(1,15)]
>>> estimate = [random.gauss(0, 1) for i in idx]
>>> reported = [e + .05 * random.gauss(0, 1) for e in estimate]
>>> p = pandas.DataFrame({'estimate': estimate, 'reported': reported},
...     index=idx)
>>> f = nums.SimpleFrame({'name': 'test'}, backend, frame=p)
>>> f.more = '*' * 10  # Add some more data in a property to save.
>>> f.save()
>>> g = backend.load({'name': 'test'}, allow_load=True)
>>> all(g.frame == f.frame) and f.more == g.more
True
>>> shutil.rmtree(backend.root)
"""
