public function slice($offset, $length = null)
	{
		if (is_numeric($offset) && is_int(+$offset)) {
			if ($length === null || (is_numeric($length) && is_int(+$length))) {
				$this->segments = array_slice($this->segments, $offset, $length);
			} else {
				throw new \InvalidArgumentException(
					__METHOD__."() expects parameter two, length, to be null or an integer"
				);
			}
		} else {
			throw new \InvalidArgumentException(
				__METHOD__."() expects parameter one, offset, to be an integer"
			);
		}
		
		return $this;
	}