## Parameters:
-* Optional ```string $header_name```
+* Optional string $header_name
The name of the response header to retrieve.
## Returns:
-* ```string```, the compound value of the response header to send
-* ```NULL```, if the header was not found
-* ```array```, of all response headers, if $header_name was not specified
+* string, the compound value of the response header to send
+* NULL, if the header was not found
+* array, of all response headers, if $header_name was not specified