VTAssociationDB getExistingAssociationDB(Address sourceAddress, Address destinationAddress) {

		long addressKey = session.getLongFromSourceAddress(sourceAddress);
		try {
			RecordIterator iterator =
				associationTableAdapter.getRecordsForSourceAddress(addressKey);
			while (iterator.hasNext()) {
				DBRecord record = iterator.next();
				VTAssociationDB associationDB = getAssociationForRecord(record);
				Address dbDestinatonAddress = associationDB.getDestinationAddress();
				if (destinationAddress.equals(dbDestinatonAddress)) {
					return associationDB;
				}
			}
		}
		catch (IOException e) {
			session.dbError(e);
		}

		return null;
	}
Called when an existing session has been initialized with its programs.  This is not called
when a new session is created.
Ghidra/Features/VersionTracking/src/main/java/ghidra/feature/vt/api/db/AssociationDatabaseManager.java