"Events provide optional notifications" code sample incomplete

### Type of issue

Missing information

### Description

[Section link](https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/types/delegates-lambdas#events-provide-optional-notifications). "Walking through the code" section provides explanation to code that is missing in the code sample.

### Page URL

https://learn.microsoft.com/en-us/dotnet/csharp/fundamentals/types/delegates-lambdas

### Content source URL

https://github.com/dotnet/docs/blob/main/docs/csharp/fundamentals/types/delegates-lambdas.md

### Document Version Independent Id

d4c5e48c-8ae5-7008-3b99-a282cd6c2e30

### Platform Id

529dd813-c00a-db16-dac8-b2501fbe22be

### Article author

@BillWagner

### Metadata

* ID: 0149633d-12a7-37c8-64fa-4746d6a10e0f
* PlatformId: 529dd813-c00a-db16-dac8-b2501fbe22be
* Service: **dotnet-csharp**
* Sub-service: **fundamentals**

[Related Issues](https://github.com/dotnet/docs/issues?q=is%3Aissue+is%3Aopen+d4c5e48c-8ae5-7008-3b99-a282cd6c2e30)

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