### Question:
AimdCongestionController implements CongestionController { @Override public boolean hasInFlight() { return is(this.amountInFlight.get()).greaterThan(UnsignedLong.ZERO); } AimdCongestionController();  AimdCongestionController(
      final UnsignedLong startAmount, final UnsignedLong increaseAmount, final BigDecimal decreaseFactor,
      final CodecContext streamCodecContext
  ); @Override UnsignedLong getMaxAmount(); @Override void prepare(final UnsignedLong amount); @Override void fulfill(final UnsignedLong prepareAmount); @Override void reject(final UnsignedLong prepareAmount, final InterledgerRejectPacket rejectPacket); @Override CongestionState getCongestionState(); void setCongestionState(final CongestionState congestionState); @Override Optional<UnsignedLong> getMaxPacketAmount(); void setMaxPacketAmount(final UnsignedLong maxPacketAmount); void setMaxPacketAmount(final Optional<UnsignedLong> maxPacketAmount); @Override boolean hasInFlight();  }### Answer:
@Test public void hasInFlight() { controller.prepare(UnsignedLong.ONE); assertThat(controller.hasInFlight()).isTrue(); }