public function insert($offset, $value)
	{
		$offset = $this->normalizeKey($offset);
		$value  = $this->normalizeValue($value);

		// Insert the value at given offset. We put the value into an array so that array_splice()
		// won't insert it as multiple elements if it happens to be an array
		array_splice($this->items, $offset, 0, [$value]);

		return $value;
	}