The World Provider interface is used to get even more information out of an IWorld object.

It might be required for you to import the package if you encounter any issues, so better be safe than sorry and add the import.
import crafttweaker.world.IWorldProvider;

Normally, you can just get the worldProvider from an IWorld object or some functions, though if yo need to create one yourself, here's how you do it:
Note that this method should only be called inside functions that are meant to be run inside minecraft, not during the loading circle.

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crafttweaker.world.IWorldProvider.getFromID(int id);

ZenGetter	ZenMethod	Return Type
ZenGetter actualHeight	ZenMethod getActualHeight()	Return Type int
ZenGetter actualGroundLevel	ZenMethod getAverageGroundLevel()	Return Type int
ZenGetter cloudHeight	ZenMethod getCloudHeight()	Return Type float
ZenGetter currentMoonPhaseFactor	ZenMethod getCurrentMoonPhaseFactor()	Return Type float
ZenGetter dimensionID	ZenMethod getDimensionID()	Return Type int
ZenGetter height	ZenMethod getHeight()	Return Type int
ZenGetter horizon	ZenMethod getHorizon()	Return Type double
ZenGetter lightBrightnesTable	ZenMethod getLightBrightnesTable()	Return Type float[]
ZenGetter movementFactor	ZenMethod getMovementFactor()	Return Type double
ZenGetter randomizedSpawnPoint	ZenMethod getRandomizedSpawnPoint()	Return Type IBlockPos
ZenGetter saveFolder	ZenMethod getSaveFolder()	Return Type string
ZenGetter seed	ZenMethod getSeed()	Return Type long
ZenGetter spawnCoordinate	ZenMethod getSpawnCoordinate()	Return Type IBlockPos
ZenGetter spawnPoint	ZenMethod getSpawnPoint()	Return Type IBlockPos
ZenGetter voidFogYFactor	ZenMethod getVoidFogYFactor()	Return Type double
ZenGetter worldTime	ZenMethod getWorldTime()	Return Type long
ZenGetter canRespawnHere	ZenMethod canRespawnHere()	Return Type bool
ZenGetter waterVaporize	ZenMethod doesWaterVaporize()	Return Type bool
ZenGetter skylight	ZenMethod hasSkyLight()	Return Type bool
ZenGetter daytime	ZenMethod isDaytime()	Return Type bool
ZenGetter nether	ZenMethod isNether()	Return Type bool
ZenGetter skyColored	ZenMethod isSkyColored()	Return Type bool
ZenGetter surfaceWorld	ZenMethod isSurfaceWorld()	Return Type bool

Use either an IBlockPos object.
Returns an IBiome Object.

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worldProvObj.getBiome(IBlockPos position);

Use a long.
Returns an int.

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worldProvObj.getMoonPhase(long time);

Use an IPlayer object.
Returns a new IWorldProvider object.

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worldProvObj.getRespawnDimension(IPlayer player);

Use a float.
Returns a float.

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worldProvObj.getStarBrightness(float something);
worldProvObj.getSunBrightness(float something);
worldProvObj.getSunBrightnessFactor(float something);

Use an IBlockPos object.
Returns a boolean.

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worldProvObj.isBlockHighHumidity(IBlockPos pos);