private void clearChanges() {

		// trick each program to think that it hasn't been changed so that the merge process 
		// ignores all the work done so far
		latestProgram.setChangeSet(new ProgramDBChangeSet(resultProgram.getAddressMap(), 20));
		resultProgram.setChangeSet(new ProgramDBChangeSet(resultProgram.getAddressMap(), 20));
		privateProgram.setChangeSet(new ProgramDBChangeSet(resultProgram.getAddressMap(), 20));
		originalProgram.setChangeSet(new ProgramDBChangeSet(resultProgram.getAddressMap(), 20));
	}
The non-preferred way of configuring tests for merge testing, which is to use real
programs that are files on disk.  You should try to use the
{@link InMemoryProgramMTFModel} by using 
{@link MergeTestFacilitator#initialize(String, MergeProgramModifier)} when writing
merge tests.
Ghidra/Features/Base/src/test/java/ghidra/program/database/RealProgramMTFModel.java