code/user/provider/model.php
public function findUser($identifier)
    {
        $user = null;
        if($this->isLoaded($identifier))
        {
            if (!is_numeric($identifier)) {
                $user = $this->_emails[$identifier];
            } else {
                $user = parent::findUser($identifier);
            }
        }

        return $user;
    }
public function findUser($identifier)
    {
        $user = null;
        if($this->isLoaded($identifier))
        {
            if (!is_numeric($identifier)) {
                $user = $this->_emails[$identifier];
            } else {
                $user = parent::findUser($identifier);
            }
        }

        return $user;
    }
public function findUser ( $ identifier ) { $ user = null ; if ( $ this -> isLoaded ( $ identifier ) ) { if ( ! is_numeric ( $ identifier ) ) { $ user = $ this -> _emails [ $ identifier ] ; } else { $ user = parent :: findUser ( $ identifier ) ; } } return $ user ; }
Find a user for the given identifier

@param string $identifier A unique user identifier, (i.e a username or email address)
@return UserInterface|null Returns a UserInterface object or NULL if the user hasn't been loaded yet
Find a user for the given identifier