Macro plugin 

macro_rules! plugin {
    (
        metadata: $metadata:expr_2021,
        $(startup_policy: $startup_policy:expr_2021,)?
        $(provides: [$($provide:expr_2021),* $(,)?],)?
        $(config: [$($config:expr_2021),* $(,)?],)?
        $(web_ui: [$($web_ui:expr_2021),* $(,)?],)?
        $(mesh: [$($mesh:expr_2021),* $(,)?],)?
        $(events: [$($event:expr_2021),* $(,)?],)?
        $(mcp: [$($mcp:expr_2021),* $(,)?],)?
        $(http: [$($http:expr_2021),* $(,)?],)?
        $(inference: [$($inference:expr_2021),* $(,)?],)?
        $(health: $health:expr_2021,)?
        $(on_initialized: $on_initialized:expr_2021,)?
        $(on_channel_message: $on_channel_message:expr_2021,)?
        $(on_mesh_event: $on_mesh_event:expr_2021,)?
    ) => { ... };
}