default void upgrade(
            ManagedAsyncClientConnection conn,
            HttpHost endpointHost,
            NamedEndpoint endpointName,
            Object attachment,
            HttpContext context,
            FutureCallback<ManagedAsyncClientConnection> callback) {
        upgrade(conn, endpointHost, attachment);
        if (callback != null) {
            callback.completed(conn);
        }
    }
Upgrades transport security of the given managed connection
by using the TLS security protocol.

@param conn the managed connection.
@param endpointHost the address of the remote endpoint.
@param endpointName the name of the remote endpoint, if different from the endpoint host name,
                  {@code null} otherwise. Usually taken from the request URU authority.
@param attachment the attachment, which can be any object representing custom parameter
                   of the operation.
@param context the execution context.
@param callback the future result callback.
@since 5.4
httpclient5/src/main/java/org/apache/hc/client5/http/nio/AsyncClientConnectionOperator.java