Macro opcua_core::register_runtime_component

macro_rules! register_runtime_component {
    ( $component_name:expr ) => { ... };
}

This macro is for debugging purposes - code register a running component (e.g. tokio task) when it starts and calls the corresponding deregister macro when it finishes. This enables the code to print out a list of components in existence at any time to ensure they were properly cleaned up.