`DataFrame.add` and `DataFrame.radd` are the same function
In 0.22 (and 0.23), there are two copies of the same function `DataFrame.add` and `DataFrame.radd`. The link in the documentation also points to the same function in the source code. Here are the documentation links for the two functions:

[`DataFrame.add`](https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.add.html)

[`DataFrame.radd`](https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.radd.html)
