| accumulate | Split-Apply-Combine with Collapsing Groups |
| csh_from_digits | Derive collapsing scheme from hierarchical classification |
| cumulate | Split-Apply-Combine with Collapsing Groups |
| frac_complete | Demand minimal fraction of complete records |
| from_validator | Use a validate::validator object to test a group |
| min_complete | Demand minimal number of complete records |
| min_records | Demand minimal number of functons |
| producers | synthetic data on producers |
| smoke_test | Test your testing function for common edge cases |