@Override public final UserAccount findUserAccountByUsername(final String username) { if (username == null) { throw new IllegalArgumentException("The passed username was null."); } final Selector selector = connectionPool.createSelector(); final List<Column> columns = selector.getColumnsFromRow(COLUMN_FAMILY_USERNAME, username, false, CONSISTENCY_LEVEL_READ); if (!columns.isEmpty()) { final String userid = Selector.getColumnStringValue(columns, "userid"); return findUserAccountByPrimaryKey(userid); } return null; }