IntervalArray.closed Whether the intervals are closed on the left-side, right-side, both or neither
© 2008–2012, AQR Capital Management, LLC, Lambda Foundry, Inc. and PyData Development Team
Licensed under the 3-clause BSD License.
https://pandas.pydata.org/pandas-docs/version/0.25.0/reference/api/pandas.arrays.IntervalArray.closed.html