CaseInsensitiveDictionary

21class CaseInsensitiveDictionary implements ArrayAccess, IteratorAggregate {22	/**23	 * Actual item data24	 *25	 * @var array26	 */27	protected $data = [];28 29	/**30	 * Creates a case insensitive dictionary.31	 *32	 * @param array $data Dictionary/map to convert to case-insensitive33	 */34	public function __construct(array $data = []) {35		foreach ($data as $offset => $value) {36			$this->offsetSet($offset, $value);37		}38	}39 40	/**41	 * Check if the given item exists42	 *43	 * @param string $offset Item key44	 * @return boolean Does the item exist?45	 */46	#[ReturnTypeWillChange]47	public function offsetExists($offset) {48		if (is_string($offset)) {49			$offset = strtolower($offset);50		}51 52		return isset($this->data[$offset]);53	}54 55	/**56	 * Get the value for the item57	 *58	 * @param string $offset Item key59	 * @return string|null Item value (null if the item key doesn't exist)60	 */61	#[ReturnTypeWillChange]62	public function offsetGet($offset) {63		if (is_string($offset)) {64			$offset = strtolower($offset);65		}66 67		if (!isset($this->data[$offset])) {68			return null;69		}70 71		return $this->data[$offset];72	}73 74	/**75	 * Set the given item76	 *77	 * @param string $offset Item name78	 * @param string $value Item value79	 *80	 * @throws \WpOrg\Requests\Exception On attempting to use dictionary as list (`invalidset`)81	 */82	#[ReturnTypeWillChange]83	public function offsetSet($offset, $value) {84		if ($offset === null) {85			throw new Exception('Object is a dictionary, not a list', 'invalidset');86		}87 88		if (is_string($offset)) {89			$offset = strtolower($offset);90		}91 92		$this->data[$offset] = $value;93	}94 95	/**96	 * Unset the given header97	 *98	 * @param string $offset The key for the item to unset.99	 */100	#[ReturnTypeWillChange]