@Override
		public int hashCode() {
			int hashCode = MurmurHash.initialize();
			hashCode = MurmurHash.update(hashCode, ruleIndex);
			hashCode = MurmurHash.update(hashCode, predIndex);
			hashCode = MurmurHash.update(hashCode, isCtxDependent ? 1 : 0);
			hashCode = MurmurHash.finish(hashCode, 3);
			return hashCode;
		}
The default {@link SemanticContext}, which is semantically equivalent to
a predicate of the form {@code {true}?}.
runtime/Java/src/org/antlr/v4/runtime/atn/SemanticContext.java