**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.
#pragma once
#include <Parsers/ASTConstraintDeclaration.h>
#include <Interpreters/ExpressionActions.h>
#include <Interpreters/TreeCNFConverter.h>
#include <Interpreters/ComparisonGraph.h>
namespace DB
{
using ConstraintsExpressions = std::vector<ExpressionActionsPtr>;
struct ConstraintsDescription
{
public:
    ConstraintsDescription() { update(); }
    ConstraintsDescription(const ASTs & constraints_);
    ConstraintsDescription(const ConstraintsDescription & other);
    ConstraintsDescription & operator=(const ConstraintsDescription & other);
    bool empty() const { return constraints.empty(); }
    String toString() const;
    static ConstraintsDescription parse(const String & str);
    enum class ConstraintType : UInt8
    {