def get_frt_hours(forecast_reference_time: DimCoord) -> Set[int]:
"""
Returns a set of integer representations of the hour of the
forecast reference time.
Args:
forecast_reference_time:
The forecast_reference_time coordinate to extract the hours from.
Returns:
A set of integer representations of the forecast reference time
hours.
"""
frt_hours = []
for frt in forecast_reference_time.cells():
frt_hours.append(np.int32(frt.point.hour))
return set(frt_hours)
