private void referencePrimaryChanged(Reference ref) {
		if (ref.isPrimary()) {
			program.setObjChanged(ProgramEvent.REFERNCE_PRIMARY_SET, ref.getFromAddress(), ref,
				null, ref);
		}
		else {
			program.setObjChanged(ProgramEvent.REFERENCE_PRIMARY_REMOVED, ref.getFromAddress(), ref,
				ref, null);
		}
	}
Removes the external entry point at the given address
@param addr that address at which to remove the external entry point attribute.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/references/ReferenceDBManager.java