Get available layouts from flexible content class

functions.php

$class = new ReflectionClass('\SS_ACF\Components\FlexibleContent');
$methods = $class->getMethods(ReflectionMethod::IS_PUBLIC);
asort($methods);
foreach ($methods as $function) {
    if ($function->class === 'SS_ACF\Components\FlexibleContent') {
        echo "'{$function->name}',<br>";
    }
}