- Improve efficiency with copying
- Refactor init
- implement iloc, iat
- think about str/repr
- consider naming: contains, is_superset_of, is_contained_in, is_subset_of, intersects_elementwise, is_separated_from, overlap
- binning
- Use numba.jit
- refactor tests using dataframes
- test for str/repr methods
- heterogenous tst for element-wise operations
- empty size in vectorizer