public function removeHeader($field)
    {
        $ucField = strtoupper($field);

        if ($ucField === 'SET-COOKIE') {
            $this->cookies = [];
        } elseif (isset($this->ucHeaders[$ucField])) {
            $field = $this->ucHeaders[$ucField];
            unset(
                $this->ucHeaders[$ucField],
                $this->headers[$field]
            );
        }

        return $this;
    }