**Use case**

```
Received exception from server (version 21.11.1):
Code: 36. DB::Exception: Received from localhost:9000. DB::Exception: Wrong index name. Cannot find index `test_pentagram` to drop.. (BAD_ARGUMENTS)

github-explorer.ru-central1.internal :) ALTER TABLE hackernews DROP INDEX text_pentagram
```

It did not show me the typo.
: definition_ast(other.definition_ast ? other.definition_ast->clone() : nullptr)
    , expression_list_ast(other.expression_list_ast ? other.expression_list_ast->clone() : nullptr)
    , name(other.name)
    , type(other.type)
    , arguments(other.arguments)
    , column_names(other.column_names)
    , data_types(other.data_types)
    , sample_block(other.sample_block)
    , granularity(other.granularity)
{
    if (other.expression)
        expression = other.expression->clone();
}
IndexDescription & IndexDescription::operator=(const IndexDescription & other)