Definitions are not supported in DI YamlDumper / YamlFileLoader

| Q             | A
| ------------- | ---
| Bug fix?      | [yes]
| New feature?  | [yes|no]
| BC breaks?    | [yes|no]
| Deprecations? | [yes|no]
| Tests pass?   | [yes|no]
| Fixed tickets | [comma separated list of tickets fixed by the PR]
| License       | MIT
| Doc PR        | [The reference to the documentation PR if any]