### Question:
SpeedCalculator { public String lastSpeed() { return humanReadableSpeed(bytesPerSecond, true); }  synchronized void reset(); synchronized void downloading(long increaseBytes); synchronized void flush(); long getInstantBytesPerSecondAndFlush(); synchronized long getBytesPerSecondAndFlush(); synchronized long getBytesPerSecondFromBegin(); synchronized void endTask(); String instantSpeed(); String speed(); String lastSpeed(); synchronized long getInstantSpeedDurationMillis(); String getSpeedWithBinaryAndFlush(); String getSpeedWithSIAndFlush(); String averageSpeed(); String speedFromBegin();  }### Answer:
@Test public void lastSpeed() { calculator.bytesPerSecond = 1; assertThat(calculator.lastSpeed()).isEqualTo("1 B/s"); }