updated documentation of `sanitize_dataframe`
@@ -171,6 +171,8 @@ def sanitize_dataframe(df):
* Convert np.int dtypes to Python int objects
* Convert floats to objects and replace NaNs/infs with None.
* Convert DateTime dtypes into appropriate string representations
+ * Convert Nullable integers to objects and replace NaN with None
+ * convert dedicated string column to objects and replace NaN with None
* Raise a ValueError for TimeDelta dtypes
"""
df = df.copy()
