presto-tpch/src/main/java/io/prestosql/plugin/tpch/TpchMetadata.java/TpchMetadata/toDouble
class TpchMetadata:    private static double toDouble(Object value, Type columnType)
    {
        if (value instanceof String && columnType.equals(DATE)) {
            return LocalDate.parse((CharSequence) value).toEpochDay();
        }
        if (columnType.equals(BIGINT) || columnType.equals(INTEGER) || columnType.equals(DATE)) {
            return ((Number) value).longValue();
        }
        if (columnType.equals(DOUBLE)) {
            return ((Number) value).doubleValue();
        }
        throw new IllegalArgumentException("unsupported column type " + columnType);
    }