presto-jdbc/src/main/java/io/prestosql/jdbc/PrestoResultSet.java/PrestoResultSet/column
class PrestoResultSet:    private Object column(int index)
            throws SQLException
    {
        checkOpen();
        checkValidRow();
        if ((index <= 0) || (index > resultSetMetaData.getColumnCount())) {
            throw new SQLException("Invalid column index: " + index);
        }
        Object value = row.get().get(index - 1);
        wasNull.set(value == null);
        return value;
    }