public function stem($token) 
    {
        if(array_key_exists($token, $this->dictionary)){
            return $this->dictionary[$token];
        }
        return $token;
    }
public function stem($token) 
    {
        if(array_key_exists($token, $this->dictionary)){
            return $this->dictionary[$token];
        }
        return $token;
    }
public function stem ( $ token ) { if ( array_key_exists ( $ token , $ this -> dictionary ) ) { return $ this -> dictionary [ $ token ] ; } return $ token ; }
Returns a token's stemmed root
@param string $token
@return string
Returns a token s stemmed root