code: public boolean removeExecutedTradeCallback(final BitfinexExecutedTradeSymbol tradeSymbol,
  			final BiConsumer<BitfinexExecutedTradeSymbol, BitfinexExecutedTrade> callback) throws BitfinexClientException {
  
  		return tradesCallbacks.removeCallback(tradeSymbol, callback);
  	}
docs: Remove a executed trade callback
  @param symbol
  @param callback
  @return
  @throws BitfinexClientException