CLN: remove unnecessary __getitem__ override

Author: toobaz

pandas/core/sparse/frame.py

@@ -428,18 +428,6 @@ def _sanitize_column(self, key, value, **kwargs):
         # always return a SparseArray!
         return clean
 
-    def __getitem__(self, key):
-        """
-        Retrieve column or slice from DataFrame
-        """
-        if isinstance(key, slice):
-            date_rng = self.index[key]
-            return self.reindex(date_rng)
-        elif isinstance(key, (np.ndarray, list, Series)):
-            return self._getitem_array(key)
-        else:
-            return self._get_item_cache(key)
-
     def get_value(self, index, col, takeable=False):
         """
         Quickly retrieve single value at passed column and index