src/Whip.php
public function addCustomHeader($header)
    {
        self::$headers[self::CUSTOM_HEADERS][] = $this->normalizeHeaderName($header);
        return $this;
    }
public function addCustomHeader($header)
    {
        self::$headers[self::CUSTOM_HEADERS][] = $this->normalizeHeaderName($header);
        return $this;
    }
public function addCustomHeader ( $ header ) { self :: $ headers [ self :: CUSTOM_HEADERS ] [ ] = $ this -> normalizeHeaderName ( $ header ) ; return $ this ; }
Adds a custom header to the list.
@param string $header The custom header to add.
@return Whip Returns $this.
Adds a custom header to the list .