public IntervalSet LOOK(ATNState s, RuleContext ctx) {
		return LOOK(s, null, ctx);
   	}
Compute set of tokens that can follow {@code s} in the ATN in the
specified {@code ctx}.

<p>If {@code ctx} is {@code null} and the end of the rule containing
{@code s} is reached, {@link Token#EPSILON} is added to the result set.
If {@code ctx} is not {@code null} and the end of the outermost rule is
reached, {@link Token#EOF} is added to the result set.</p>

@param s the ATN state
@param ctx the complete parser context, or {@code null} if the context
should be ignored

@return The set of tokens that can follow {@code s} in the ATN in the
specified {@code ctx}.
runtime/Java/src/org/antlr/v4/runtime/atn/LL1Analyzer.java