protected BitSet getConflictingAlts(ATNConfigSet configs) {
		Collection<BitSet> altsets = PredictionMode.getConflictingAltSubsets(configs);
		return PredictionMode.getAlts(altsets);
	}
Gets a {@link BitSet} containing the alternatives in {@code configs}
which are part of one or more conflicting alternative subsets.

@param configs The {@link ATNConfigSet} to analyze.
@return The alternatives in {@code configs} which are part of one or more
conflicting alternative subsets. If {@code configs} does not contain any
conflicting subsets, this method returns an empty {@link BitSet}.
runtime/Java/src/org/antlr/v4/runtime/atn/ParserATNSimulator.java