code: public static Tuple2<String,Long> mapNoOfTransaction(BitcoinBlock block) {
  	return new Tuple2<String, Long>("No of transactions: ",(long)(block.getTransactions().size())); 
    }
docs: Maps the number of transactions of a block to a tuple
  
  @param block Bitcoinblock
  
  @return Tuple containing the String "No of transactions. " and the number of transactions as long