@API(status = API.Status.STABLE)
    public @NonNull CommandExecutionHandler<@NonNull C> commandExecutionHandler() {
        return this.commandExecutionHandler;
    }
Returns the command execution handler.
<p>
The command execution handler is invoked after a parsing a command.
It has access to the {@link org.incendo.cloud.context.CommandContext} which contains
the parsed component values.

@return the command execution handler
cloud-core/src/main/java/org/incendo/cloud/Command.java