public long throttleDelayMs(Node node, long now) {
        return connectionStates.throttleDelayMs(node.idString(), now);
    }
Returns the number of milliseconds to wait, based on the connection state, before attempting to send data. When
disconnected, this respects the reconnect backoff time. When connecting or connected, this handles slow/stalled
connections.

@param node The node to check
@param now The current timestamp
@return The number of milliseconds to wait.
clients/src/main/java/org/apache/kafka/clients/NetworkClient.java