Gian Merlino c3faa24f26
DataSchema: Improve duplicate-column error message. (#11082)
* DataSchema: Improve duplicate-column error message.

Now, when duplicate columns are specified, the error message will include
information about where those duplicate columns were seen. Also, if there
are multiple duplicate columns, all will be listed in the error message
instead of just the first one encountered.

* Fix style for checkstyle.

* Further improve error message.
2021-04-12 19:03:15 -07:00
..