presto-main/src/main/java/io/prestosql/sql/planner/optimizations/IndexJoinOptimizer.java/IndexSourceRewriter/Context
class IndexSourceRewriter:            public Context(Set<Symbol> lookupSymbols, AtomicBoolean success)
            {
                checkArgument(!lookupSymbols.isEmpty(), "lookupSymbols can not be empty");
                this.lookupSymbols = ImmutableSet.copyOf(requireNonNull(lookupSymbols, "lookupSymbols is null"));
                this.success = requireNonNull(success, "success is null");
            }