presto-main/src/main/java/io/prestosql/operator/scalar/ArrayJoin.java/ArrayJoin/ArrayJoin
class ArrayJoin:    public ArrayJoin()
    {
        super(new FunctionMetadata(
                new Signature(
                        FUNCTION_NAME,
                        ImmutableList.of(castableToTypeParameter("T", VARCHAR.getTypeSignature())),
                        ImmutableList.of(),
                        VARCHAR.getTypeSignature(),
                        ImmutableList.of(arrayType(new TypeSignature("T")), VARCHAR.getTypeSignature()),
                        false),
                false,
                ImmutableList.of(
                        new FunctionArgumentDefinition(false),
                        new FunctionArgumentDefinition(false)),
                false,
                true,
                DESCRIPTION,
                SCALAR));
    }