Set<SourceType> getReferenceSourceTypesToClear() {
		HashSet<SourceType> sourceTypesToClear = new HashSet<SourceType>();
		if (shouldClear(ClearType.USER_REFERENCES)) {
			sourceTypesToClear.add(SourceType.USER_DEFINED);
		}
		if (shouldClear(ClearType.DEFAULT_REFERENCES)) {
			sourceTypesToClear.add(SourceType.DEFAULT);
		}
		if (shouldClear(ClearType.IMPORT_REFERENCES)) {
			sourceTypesToClear.add(SourceType.IMPORTED);
		}
		if (shouldClear(ClearType.ANALYSIS_REFERENCES)) {
			sourceTypesToClear.add(SourceType.ANALYSIS);
		}
		return sourceTypesToClear;
	}
Default constructor that will clear everything!
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/clear/ClearOptions.java