public function setHeader($name, $value)
    {
        if (!$this->response->headers->has($name)) {
            $this->response->headers->set($name, $value);
        }
    }
public function setHeader($name, $value)
    {
        if (!$this->response->headers->has($name)) {
            $this->response->headers->set($name, $value);
        }
    }
public function setHeader ( $ name , $ value ) { if ( ! $ this -> response -> headers -> has ( $ name ) ) { $ this -> response -> headers -> set ( $ name , $ value ) ; } }
Set HTTP response header.

Does not allow overwriting of response headers. The first definition of
a header will be used.

@param string $name
@param string $value
Set HTTP response header .