* ``length``: The size of the slice
* ``preserve_keys``: Whether to preserve key or not (when the input is an array)
-.. _`Traversable`: http://php.net/manual/en/class.traversable.php
-.. _`array_slice`: http://php.net/array_slice
-.. _`mb_substr` : http://php.net/mb-substr
-.. _`substr`: http://php.net/substr
+.. _`Traversable`: https://secure.php.net/manual/en/class.traversable.php
+.. _`array_slice`: https://secure.php.net/array_slice
+.. _`mb_substr` : https://secure.php.net/mb-substr
+.. _`substr`: https://secure.php.net/substr