Adding DataFrame and Panel imports for tests

Author: ryankarlos

pandas/io/packers.py

@@ -62,11 +62,13 @@
 from pandas.core.arrays.categorical import Categorical
 from pandas.core.arrays.interval import Interval
 from pandas.core.arrays.sparse import BlockIndex, IntIndex
+from pandas.core.frame import DataFrame
 from pandas.core.generic import NDFrame
 from pandas.core.index import Index, MultiIndex, PeriodIndex, RangeIndex
 from pandas.core.indexes.datetimes import DatetimeIndex
 from pandas.core.indexes.interval import IntervalIndex
 from pandas.core.internals import BlockManager, _safe_reshape, make_block
+from pandas.core.panel import Panel
 from pandas.core.series import Series
 from pandas.core.sparse.api import SparseDataFrame, SparseSeries