code: public function getUsers( array $userNames ) {
  		$query = $this->db->from( 'user' )
  			->select( 'user_id', 'user_name', 'user_editcount', 'user_registration', 'ug_group' )
  			->leftJoin( 'user_groups ON user_id = ug_user' )
  			->where( 'user_name', $userNames );
  
  		$users = array();
  		$rows = $query->fetchAll();
  		
  		$userGroups = $this->getGroupsPerUser( $rows );
  
  		foreach ( $rows as $row ) {
  			$users[] = $this->getUserFromRow( $row, $userGroups[$row['user_id']] );
  		}
  
  		return $users;
  	}
docs: @param string[] $userNames
  
  @return User[]