code: private int numberOfSessionsInTransaction(String xferId) {
  		int sessionCount = 0;
  		List<String> sessions = transactionSessions.get(xferId);
  
  		if(sessions != null)
  			sessionCount = sessions.size();
  
  		return sessionCount;
  	}
docs: Returns the number of active sessions for transaction.
  
  @param xferId
  @return int