The Symfony codebase is being modernized by adding type declarations. I think that we should do the same here as well.

My suggestions:

• Example code that does not override/implement a Symfony method, should be typed.
• Example code that overrides/implements a Symfony method should be updated for 5.0 to match the added parameter type declarations.
• Example code that overrides/implements a Symfony method should turn an upstream @return annotation into an explicit return type declaration if possible. In most cases, we can do this for the 4.4 docs already.

Related:

• [5.0] Add parameter type-hints symfony#32179
• [5.0] Add return type declarations symfony#33228