src/Colorium/Http/Response.php
public function header($name, $value, $replace = true)
    {
        $name = strtolower($name);
        if(isset($this->headers[$name]) and !$replace) {
            if(is_array($this->headers[$name])) {
                array_push($this->headers[$name], $value);
            }
            else {
                $this->headers[$name] = [
                    $this->headers[$name],
                    $value
                ];
            }
        }
        else {
            $this->headers[$name] = $value;
        }

        return $this;
    }
public function header($name, $value, $replace = true)
    {
        $name = strtolower($name);
        if(isset($this->headers[$name]) and !$replace) {
            if(is_array($this->headers[$name])) {
                array_push($this->headers[$name], $value);
            }
            else {
                $this->headers[$name] = [
                    $this->headers[$name],
                    $value
                ];
            }
        }
        else {
            $this->headers[$name] = $value;
        }

        return $this;
    }
Set header

@param string $name
@param string $value
@param bool $replace

@return $this