isClimbing

   public boolean isClimbing() {
      if (this.isSpectator()) {
         return false;
      } else {
         BlockPos blockPos = this.getBlockPos();
         BlockState blockState = this.getBlockState();
         Block block = blockState.getBlock();
         if (block.isIn(BlockTags.CLIMBABLE)) {
            this.field_22418 = Optional.of(blockPos);
            return true;
         } else if (block instanceof TrapdoorBlock && this.canEnterTrapdoor(blockPos, blockState)) {
            this.field_22418 = Optional.of(blockPos);
            return true;
         } else {
            return false;
         }
      }
   }