public function ask(string $question, ?string $default = null): ?string
    {
        return $this->getOutput()->ask($question, $default);
    }
public function ask(string $question, ?string $default = null): ?string
    {
        return $this->getOutput()->ask($question, $default);
    }
public function ask ( string $ question , ? string $ default = null ) : ? string { return $ this -> getOutput ( ) -> ask ( $ question , $ default ) ; }
Prompt the user for input.

@param string      $question
@param null|string $default

@return null|string
Prompt the user for input .