Add is_running function to Node

Author: jbesraa

src/lib.rs

@@ -708,6 +708,11 @@ impl<K: KVStore + Sync + Send + 'static> Node<K> {
 		Ok(())
 	}
 
+    /// Checks if [`Node`] runtime is available.
+    pub fn is_running(&self) -> bool {
+        self.runtime.read().unwrap().is_some()
+    }
+
 	/// Disconnects all peers, stops all running background tasks, and shuts down [`Node`].
 	///
 	/// After this returns most API methods will return [`Error::NotRunning`].