Elastica\Util::toSnakeCase PHP Méthode

    public static function toSnakeCase($string)
    {
        $string = preg_replace('/([A-Z])/', '_$1', $string);
        return strtolower(substr($string, 1));
    }

 public function testToSnakeCase()
 {
     $string = 'HelloWorld';
     $this->assertEquals('hello_world', Util::toSnakeCase($string));
     $string = 'HowAreYouToday';
     $this->assertEquals('how_are_you_today', Util::toSnakeCase($string));
 }