public void setMergeFilter(ProgramMergeFilter filter) {
		if (filter != null) {
			this.mergeFilter = new ProgramMergeFilter(filter);
		}
		else {
			this.mergeFilter = new ProgramMergeFilter();
		}
	}
Set the filter that indicates which parts of the Program should be 
applied from the second program to the first program.
@param filter the filter indicating the types of differences to apply.
Ghidra/Features/Base/src/main/java/ghidra/program/util/ProgramMergeManager.java