@Override
	public boolean isEquivalent(DataType dt) {
		if (dt == null) {
			return false;
		}
		if (dt == this) {
			return true;
		}
		if (!(dt instanceof MissingBuiltInDataType)) {
			return false;
		}
		return missingBuiltInClassPath
				.equals(((MissingBuiltInDataType) dt).missingBuiltInClassPath);
	}
{@return classpath of missing built-in datatype for which this type is standing-in for}
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/MissingBuiltInDataType.java