private List<Reference> getPrimaryOverridingReferences() {
		if (primaryOverridingReferences != null) {
			return primaryOverridingReferences;
		}
		
		primaryOverridingReferences = new ArrayList<>();
		for (Reference ref : instr.getReferencesFrom()) {
			if (!ref.isPrimary() || !ref.getToAddress().isMemoryAddress()) {
				continue;
			}
			RefType type = ref.getReferenceType();
			if (type.isOverride()) {
				primaryOverridingReferences.add(ref);
			}
			else if (type.isCall() && primaryCallAddress == null) {
				primaryCallAddress = ref.getToAddress();
			}
		}
		
		return primaryOverridingReferences;
	}
Initialize the cache or any references on an instruction that would cause an override.

@return list of any program overrides
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/listing/InstructionPcodeOverride.java