# implements_repeated

> Details about the implements_repeated diagnostic produced by the Dart analyzer.



_'{0}' can only be implemented once._

## Description

The analyzer produces this diagnostic when a single class is specified more
than once in an `implements` clause.

## Example

The following code produces this diagnostic because `A` is in the list
twice:

```dart
class A {}
class B implements A, [!A!] {}
```

## Common fixes

Remove all except one occurrence of the class name:

```dart
class A {}
class B implements A {}
```

