Minecraft wiki entry for Configured_feature, associated text: netherrack_replace_blobs—Replaces all target blocks in a certain radius with another block. If it doesn't find the target block at its position, it will move down before generating until it finds one.
 state: The block to use.
Block state[show]
 target: The block to replace.
Block state[show]
 radius: Int provider between 0 and 12.
Int provider[show]