WireHttp::getResponseHeaderValues() method     
Get last HTTP response headers with multi-value headers as arrays
Use this method when you want to retrieve headers that can potentially contain multiple-values. Note that any code that iterates these values should be able to handle them being either a string or an array.
This method always returns an associative array of strings and arrays, unless you specify the
$key option in which case it can return an array, string, or NULL if the header is not present.
Usage
// basic usage
$array = $http->getResponseHeaderValues();
// usage with all arguments
$array = $http->getResponseHeaderValues(string $key = '', bool $forceArrays = false);Arguments
| Name | Type(s) | Description | 
|---|---|---|
| $key(optional) | string | Optional header name you want to get (if you only need a specific header) | 
| $forceArrays(optional) | bool | If even single-value headers should be arrays, specify true Default:false | 
Return value
array string null
API reference based on ProcessWire core version 3.0.252