public String getSerializedATN() {
		throw new UnsupportedOperationException("there is no serialized ATN");
	}
If this recognizer was generated, it will have a serialized ATN
representation of the grammar.

<p>For interpreters, we don't know their serialized ATN despite having
created the interpreter from it.</p>
runtime/Java/src/org/antlr/v4/runtime/Recognizer.java