ClassLoader connectorLoader(String connectorClassOrAlias) {
        String fullName = aliases.getOrDefault(connectorClassOrAlias, connectorClassOrAlias);
        ClassLoader classLoader = pluginClassLoader(fullName);
        if (classLoader == null) classLoader = this;
        log.debug(
            "Getting plugin class loader: '{}' for connector: {}",
            classLoader,
            connectorClassOrAlias
        );
        return classLoader;
    }
Retrieve the PluginClassLoader associated with a plugin class
@param name The fully qualified class name of the plugin
@return the PluginClassLoader that should be used to load this, or null if the plugin is not isolated.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/isolation/DelegatingClassLoader.java