Txns with 9 transactions, 16 items, and 36 non-zero elements
 Index │ Items
───────┼──────────────────────
     1 │ milk, eggs, bread
     2 │ milk, eggs, butter,…
     3 │ milk, eggs, bacon,…
     ⋮ │ ⋮
     7 │ milk, eggs, sugar
     8 │ milk, beer,…
     9 │ eggs, bacon, ham,…
