The class net.minecraft.data.worldgen.BootstapContext and the method net.minecraft.core.RegistrySetBuilder$BuildState#bootstapContext are not spelled correctly; they should be named BootstrapContext and bootstrapContext respectively. This is inferred to be a typo because every method that consumes a BootstapContext and is referenced in the VanillaRegistries class's private static final RegistrySetBuilder BUILDER is correctly named bootstrap.