presto-jdbc/src/main/java/io/prestosql/jdbc/PrestoResultSet.java/PrestoResultSet/columnIndex
class PrestoResultSet:    private int columnIndex(String label)
            throws SQLException
    {
        if (label == null) {
            throw new SQLException("Column label is null");
        }
        Integer index = fieldMap.get(label.toLowerCase(ENGLISH));
        if (index == null) {
            throw new SQLException("Invalid column label: " + label);
        }
        return index;
    }