public static function fromString(string $json): ?self
    {
        $document = \json_decode($json, true);

        if (JSON_ERROR_NONE !== \json_last_error() || !\is_array($document)) {
            return null;
        }

        return new self($document);
    }
public static function fromString(string $json): ?self
    {
        $document = \json_decode($json, true);

        if (JSON_ERROR_NONE !== \json_last_error() || !\is_array($document)) {
            return null;
        }

        return new self($document);
    }
public static function fromString ( string $ json ) : ? self { $ document = \ json_decode ( $ json , true ) ; if ( JSON_ERROR_NONE !== \ json_last_error ( ) || ! \ is_array ( $ document ) ) { return null ; } return new self ( $ document ) ; }
Create a document from a string.

@param string $json
@return Document|null
Create a document from a string .