Add new category of DataManager pre-processing blocks, "Test" blocks, alongside operations and sources, allowing you to compare sources and add assertions to your models. For example:

1. "Compare" - fails if the two input data sets don't match exactly (with exportable summary of differences)

For example, allowing you to run a well-known sample of data against your model, and verify the outputs are exactly right.

2. "Assert rule" - succeeds or fails according to the result of a user-specified formula

For example, you might define the rule "SUBSET_SUM(field1) - SUBSET_SUM(field2) = 0".