Return unique values combination from the selected columns.
This module allows you to select one or more columns from the input dataset, and returns a dataset that has only the selected columns and combined unique values from those columns.
For example, if the input dataset looks like this:
co1 | col2 | col3
A | 1 | x
B | 1 | y
C | 2 | x
A | 1 | x
And col1 and col2 are selected, the out dataset looks like this:
co1 | col2
A | 1
B | 1
C | 2
But if only col2 is selected, the output looks like this:
col2
1
2
Source code can be found in this [GitHub repo](https://github.com/Azure/custmod/tree/master/UniqueValues).
