[Mapgen] How make the mapgen in a subgame only makes jungles

[MineYoshi]

i need to know how i can make a mod that makes that only jungles be generated, or then how i do a mapgen of only jungles then?

[qwertymine3]

Not an expert, but I think that there are two options:
a) Make a mod to clear the registered biomes and register a jungle biome, so it is the only biome (v5, v7)

b) Edit the heat and humidity maps for the world, to scale 0, offeset to the value for junglebiome (all)

IDK about the new valleys mapgen though

[MineYoshi]

Not an expert, but I think that there are two options:
a) Make a mod to clear the registered biomes and register a jungle biome, so it is the only biome (v5, v7)

b) Edit the heat and humidity maps for the world, to scale 0, offeset to the value for junglebiome (all)

IDK about the new valleys mapgen though

I know that i need to do that, i mean how i do it?
(What code i need to use)