Repository: home-assistant/core
File: homeassistant/components/number/const.py (Python)

Code before:
        UnitOfTime.HOURS,
        UnitOfTime.MINUTES,
        UnitOfTime.SECONDS,
        UnitOfTime.MILLISECONDS,
        UnitOfTime.MICROSECONDS,
    },
    NumberDeviceClass.ENERGY: set(UnitOfEnergy),
    NumberDeviceClass.ENERGY_DISTANCE: set(UnitOfEnergyDistance),
    NumberDeviceClass.ENERGY_STORAGE: set(UnitOfEnergy),
    NumberDeviceClass.FREQUENCY: set(UnitOfFrequency),
    NumberDeviceClass.GAS: {
        UnitOfVolume.CENTUM_CUBIC_FEET,
        UnitOfVolume.CUBIC_FEET,
        UnitOfVolume.CUBIC_METERS,
        UnitOfVolume.LITERS,
        UnitOfVolume.MILLE_CUBIC_FEET,
    },
    NumberDeviceClass.HUMIDITY: {PERCENTAGE},
    NumberDeviceClass.ILLUMINANCE: {LIGHT_LUX},
    NumberDeviceClass.IRRADIANCE: set(UnitOfIrradiance),
    NumberDeviceClass.MOISTURE: {PERCENTAGE},
    NumberDeviceClass.NITROGEN_DIOXIDE: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.NITROGEN_MONOXIDE: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.NITROUS_OXIDE: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.OZONE: {
        CONCENTRATION_PARTS_PER_MILLION,
        CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
    },
    NumberDeviceClass.PH: {None},
    NumberDeviceClass.PM1: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.PM10: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.PM25: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.PM4: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.POWER_FACTOR: {PERCENTAGE, None},
    NumberDeviceClass.POWER: {
        UnitOfPower.MILLIWATT,
        UnitOfPower.WATT,
        UnitOfPower.KILO_WATT,
        UnitOfPower.MEGA_WATT,
        UnitOfPower.GIGA_WATT,
        UnitOfPower.TERA_WATT,
    },
    NumberDeviceClass.PRECIPITATION: set(UnitOfPrecipitationDepth),
    NumberDeviceClass.PRECIPITATION_INTENSITY: set(UnitOfVolumetricFlux),
    NumberDeviceClass.PRESSURE: set(UnitOfPressure),
    NumberDeviceClass.REACTIVE_ENERGY: set(UnitOfReactiveEnergy),
    NumberDeviceClass.REACTIVE_POWER: set(UnitOfReactivePower),
    NumberDeviceClass.SIGNAL_STRENGTH: {
        SIGNAL_STRENGTH_DECIBELS,
        SIGNAL_STRENGTH_DECIBELS_MILLIWATT,
    },

Review comment (suggestion):
```suggestion
        CONCENTRATION_PARTS_PER_BILLION,
```

Code after:
        UnitOfTime.DAYS,
        UnitOfTime.HOURS,
        UnitOfTime.MINUTES,
        UnitOfTime.SECONDS,
        UnitOfTime.MILLISECONDS,
        UnitOfTime.MICROSECONDS,
    },
    NumberDeviceClass.ENERGY: set(UnitOfEnergy),
    NumberDeviceClass.ENERGY_DISTANCE: set(UnitOfEnergyDistance),
    NumberDeviceClass.ENERGY_STORAGE: set(UnitOfEnergy),
    NumberDeviceClass.FREQUENCY: set(UnitOfFrequency),
    NumberDeviceClass.GAS: {
        UnitOfVolume.CENTUM_CUBIC_FEET,
        UnitOfVolume.CUBIC_FEET,
        UnitOfVolume.CUBIC_METERS,
        UnitOfVolume.LITERS,
        UnitOfVolume.MILLE_CUBIC_FEET,
    },
    NumberDeviceClass.HUMIDITY: {PERCENTAGE},
    NumberDeviceClass.ILLUMINANCE: {LIGHT_LUX},
    NumberDeviceClass.IRRADIANCE: set(UnitOfIrradiance),
    NumberDeviceClass.MOISTURE: {PERCENTAGE},
    NumberDeviceClass.NITROGEN_DIOXIDE: {
        CONCENTRATION_PARTS_PER_BILLION,
        CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
    },
    NumberDeviceClass.NITROGEN_MONOXIDE: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.NITROUS_OXIDE: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.OZONE: {
        CONCENTRATION_PARTS_PER_BILLION,
        CONCENTRATION_MICROGRAMS_PER_CUBIC_METER,
    },
    NumberDeviceClass.PH: {None},
    NumberDeviceClass.PM1: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.PM10: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.PM25: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.PM4: {CONCENTRATION_MICROGRAMS_PER_CUBIC_METER},
    NumberDeviceClass.POWER_FACTOR: {PERCENTAGE, None},
    NumberDeviceClass.POWER: {
        UnitOfPower.MILLIWATT,
        UnitOfPower.WATT,
        UnitOfPower.KILO_WATT,
        UnitOfPower.MEGA_WATT,
        UnitOfPower.GIGA_WATT,
        UnitOfPower.TERA_WATT,
    },
    NumberDeviceClass.PRECIPITATION: set(UnitOfPrecipitationDepth),
    NumberDeviceClass.PRECIPITATION_INTENSITY: set(UnitOfVolumetricFlux),
    NumberDeviceClass.PRESSURE: set(UnitOfPressure),
    NumberDeviceClass.REACTIVE_ENERGY: set(UnitOfReactiveEnergy),
    NumberDeviceClass.REACTIVE_POWER: set(UnitOfReactivePower),