public boolean isUndefined(Address start, Address end) {
		if (!start.getAddressSpace().equals(end.getAddressSpace())) {
			return false;
		}
		if (!program.getMemory().contains(start, end)) {
			return false;
		}
		if (getInstructionContaining(start, false) != null) {
			return false;
		}
		if (getDefinedDataContaining(start) != null) {
			return false;
		}
		AddressRange range = new AddressRangeImpl(start, end);
		Instruction inst = getInstructionAfter(start);
		if (inst != null) {
			Address addr = inst.getMinAddress();
			if (range.contains(addr)) {
				return false;
			}
		}
		Data data = getDefinedDataAfter(start);
		if (data != null) {
			Address addr = data.getMinAddress();
			if (range.contains(addr)) {
				return false;
			}
		}
		return true;

	}
Checks if all the addresses from start to end have undefined data.
@param start the first address in the range to check.
@param end the last address in the range to check.
@return true if all the addresses in the range have undefined data.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/code/CodeManager.java