Based on Building a Reactive Library from Scratch by Ryan Carniato.
❯ go run main.go
1. Create Signal
2. Create Reaction
The count is 0
3. Set the count to 5
The count is 5
4. Set the count to 10
The count is 10
1. Create
My name is John Smith
2. Set showFullName: false
My name is John
3. Change lastName
4. Set showFullName: true
My name is John Legend