public static function background(string $executable): self
    {
        $self = new self($executable);
        $self->background = true;

        return $self;
    }
public static function background(string $executable): self
    {
        $self = new self($executable);
        $self->background = true;

        return $self;
    }
public static function background ( string $ executable ) : self { $ self = new self ( $ executable ) ; $ self -> background = true ; return $ self ; }
Will run the command in the background and will survive even if the
current process ends

You will not have access to the process output nor if the process is
still running
Will run the command in the background and will survive even if the current process ends