:()

BlockRegistrar.java

interface BlockRegistrar {
  public static net.minecraft.block.Block BLOCK = null;
  
  public static void registerBlock(net.minecraft.util.Identifier name) {
    // whatever
  }
}

SomeBlockReg.java

class SomeBlockReg implements BlockRegistrar {
  public static net.minecraft.block.Block BLOCK = new SomeBlock();
  
  public static void register(String prefix) {
    net.minecraft.util.Identifier name = ident(prefix, __, "some_block");
    
    registerBlock(name);
  }
}