Benchmark: timing 100 iterations of chunk, line_by_line...
     chunk:  3 wallclock secs ( 1.58 usr +  0.70 sys =  2.28 CPU) @ 43.80/s (n=100)
     line_by_line: 12 wallclock secs ( 9.54 usr +  0.72 sys = 10.27 CPU) @  9.74/s (n=100)