presto-main/src/main/java/io/prestosql/metadata/LiteralFunction.java/LiteralFunction/LiteralFunction
class LiteralFunction:    public LiteralFunction()
    {
        super(new FunctionMetadata(
                new Signature(
                        LITERAL_FUNCTION_NAME,
                        ImmutableList.of(typeVariable("F"), typeVariable("T")),
                        ImmutableList.of(),
                        new TypeSignature("T"),
                        ImmutableList.of(new TypeSignature("F")),
                        false),
                false,
                ImmutableList.of(new FunctionArgumentDefinition(false)),
                true,
                true,
                "literal",
                SCALAR));
    }