Stone Layer Generation

Completion Requirements
A script that is able to generate a modifiable amount of different stone layers that supports biome changes and layer type requests.
Example layer functions to think about:

StoneLayerGen.addGlobalLayer(Layer, layer); // add a new layer that is applied to all biomes
StoneLayerGen.addLayerExclude(Layer layer, Biome biome); //adds a layer to everywhere except the biome specified.
StoneLayerGen.addLayer(Layer layer, Biome biome);
StoneLayerGen.getLayerType(int checkHeight, Biome currentBiome);

Code Recommendations
Separate Class Type for 'Layer'
Layers generate based on the number of layers added in, for example:

StoneLayerGen.addGlobalLayer(stonelayer1);
StoneLayerGen.addGlobalLayer(stonelayer2);

The world will generate with the top half of the world as stonelayer1 and the bottom half as stonelayer2.
If you add in a third layer after that, stonelayer2 becomes the middle layer and stonelayer3 the bottom layer.

Maybe add thickness to layers, as an optional input.