private String getXRefHeaderString(CodeUnit cu) {
		if (cu == null) {
			return null;
		}
		Program prog = cu.getProgram();
		int xrefCount = prog.getReferenceManager().getReferenceCountTo(cu.getMinAddress());
		List<Reference> offcuts = XReferenceUtils.getOffcutXReferences(cu, maxXRefs);
		int offcutCount = offcuts.size();

		if (offcutCount > 0) {
			String modifier = "";
			if (offcutCount == maxXRefs) {
				modifier = "+";
			}
			return "XREF[" + xrefCount + "," + offcutCount + modifier + "]: ";
		}

		if (xrefCount > 0) {
			return "XREF[" + xrefCount + "]: ";
		}
		return null;
	}
Constructor
@param model the model that the field belongs to.
@param hlProvider the HighlightProvider.
@param displayOptions the Options for display properties.
@param fieldOptions the Options for field specific properties.
Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/field/XRefHeaderFieldFactory.java