add static method
Adds a middleware to the global registry.
Registration is idempotent by instance identity.
If token is provided, registration is unique per token:
adding another middleware with the same token replaces the previous one.
Implementation
static LevitReactiveMiddleware add(
LevitReactiveMiddleware middleware, {
Object? token,
}) {
if (token == null) return _addUntokened(middleware);
final existingByToken = _middlewaresByToken[token];
if (identical(existingByToken, middleware)) return middleware;
if (existingByToken != null) {
return _replaceTokenized(token, existingByToken, middleware);
}
if (_middlewares.contains(middleware)) {
return _attachToken(token, middleware);
}
return _addTokenized(token, middleware);
}