**Use case**

```
CREATE TABLE t
(
    x UInt8,
    y UInt8,
)
```
{
    ParserKeyword s_comment("COMMENT");
    ParserStringLiteral string_literal_parser;
    ASTPtr comment;
    s_comment.ignore(pos, expected) && string_literal_parser.parse(pos, comment, expected);
    return comment;
}
}
bool ParserNestedTable::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)