public function input($key = null, $default = null)
    {
        $input = $this->getInputSource();

        return $this->inputSift($input, $key, $default);
    }
public function input($key = null, $default = null)
    {
        $input = $this->getInputSource();

        return $this->inputSift($input, $key, $default);
    }
public function input ( $ key = null , $ default = null ) { $ input = $ this -> getInputSource ( ) ; return $ this -> inputSift ( $ input , $ key , $ default ) ; }
Retrieves an input.

@param null $key     - The input's key
@param null $default - The input $key's default value

@return mixed
Retrieves an input .