presto-parser/src/main/java/io/prestosql/sql/parser/AstBuilder.java/AstBuilder/visitShowGrants
class AstBuilder:    @Override
    public Node visitShowGrants(SqlBaseParser.ShowGrantsContext context)
    {
        Optional<QualifiedName> tableName = Optional.empty();

        if (context.qualifiedName() != null) {
            tableName = Optional.of(getQualifiedName(context.qualifiedName()));
        }

        return new ShowGrants(
                getLocation(context),
                context.TABLE() != null,
                tableName);
    }