watchPylon<T> method
Builds a widget that watches the Stream from the nearest MutablePylon of type T
using a StreamBuilder, rendering via the provided builder function with initial data
from the current Pylon value or a shrunk widget if no data available.
Implementation
Widget watchPylon<T>(Widget Function(T data) builder) => StreamBuilder<T>(
stream: streamPylon<T>(),
initialData: pylonOr<T>(),
builder: (context, snap) =>
snap.hasData ? builder(snap.data as T) : const SizedBox.shrink(),
);