code: public FutureOperation unsubscribeExecutedTrades(final BitfinexExecutedTradeSymbol tradeSymbol) {
  		final FutureOperation future = new FutureOperation(tradeSymbol);
  		pendingUnsubscribes.registerFuture(future);
  
  		final UnsubscribeChannelCommand command = new UnsubscribeChannelCommand(tradeSymbol);
  		client.sendCommand(command);
  		
  		return future;
  	}
docs: Unsubscribe a executed trades channel
  @param currencyPair
  @param orderBookPrecision
  @param orderBookFrequency
  @param pricePoints
  @return