/**
* Returns a specific HTTP header, based on it's name.
*
* The name must be treated as case-insensitive.
* If the header does not exist, this method must return null.
*
* If a header appeared more than once in a HTTP request, this method will
* concatenate all the values with a comma.
*
* Note that this not make sense for all headers. Some, such as
* `Set-Cookie` cannot be logically combined with a comma. In those cases
* you *should* use getHeaderAsArray().
*
* @param string $name
* @return string|null
*/
function getHeader($name)
{
return $this->inner->getHeader($name);
}
