Wrong snake-case when filed name contains number

[HosamHasanRamadan]

Actual
Field name : immediateSpo2Threshold -> Snake Case: immediate_spo2threshold

Expected:
Field name : immediateSpo2Threshold -> Snake Case: immediate_spo2_threshold

@MappableClass(
  caseStyle: CaseStyle.snakeCase,
)
class Thresholds with ThresholdsMappable {
  final int immediateSpo2Threshold;
   const Thresholds({
    required this.immediateSpo2Threshold,
  });
}