Modules
run values through a list of stages
report Ekorn::Pipeline's errors at the caller's line
a stage made afresh for each run, told when the values run out
pipe and tap methods, running an object through stages
stages gathering values: batch and collect
stages taking or dropping values: take, drop, take_while and drop_while
stages run for their side effects: peek, count_into and dump_to
end a pipeline early