I've run into this problem a couple of times already... I'm working with IntelliJ, and some methods just don't exist (and unlike other methods, I'm not given the option to import them).
For example, I want to use the method onBlockHarvest() of the class Block, which I've seen on the documentation, but it gives an error: "Cannot resolve method 'onBlockHarvested' in 'Block'".
Another example is, i want to use the field ROCK of the class Material, but I get "Cannot resolve symbol 'ROCK'". Strangely enough it accepts Material.Stone??
I have the latest version 1.16.5.