WireHttp::getResponseHeaders() method    
Get the last HTTP response headers (associative array)
All headers are translated to [key => value] properties in the array. The keys are always lowercase and the values are always strings. If you
need multi-value headers, use the WireHttp::getResponseHeaderValues() method
instead, which returns multi-value headers as arrays. 
This method always returns an associative array of strings, unless you specify the
$key option in which case it will return a string, or NULL if the header is not present.
Usage
// basic usage
$array = $http->getResponseHeaders();
// usage with all arguments
$array = $http->getResponseHeaders(string $key = '');Arguments
| Name | Type(s) | Description | 
|---|---|---|
| $key(optional) | string | Optional header name you want to get (if you only need one) | 
Return value
array string null
See Also
API reference based on ProcessWire core version 3.0.252