Consider making ledger and entries custom objects

[acook]

The ledger itself is an array which returns structured arrays of each method call it received:

[[method_name, arguments_sent_to_method, block_passed_to_method], ...]

But you have to know the structure or look it up every time to make sure you know what is what. If instead the ledger returned objects (even just OpenStruct) which provided those values directly or optionally converted to an array, it might require less time consulting the documentation.

We could also add interesting methods to the ledger which could extract different dimensions of that data directly (like the list of methods only as demonstrated below).

imp.impasta.ledger.first.caller #=> caller stacktrace
imp.impasta.ledger.messages #=> [:foo, :bar, :baz]