code: @Nullable
      BTree loadMetaTree(final long rootAddress, final LogTip logTip) {
          if (rootAddress < 0 || rootAddress >= logTip.highAddress) return null;
          return new BTree(log, getBTreeBalancePolicy(), rootAddress, false, META_TREE_ID) {
              @NotNull
              @Override
              public DataIterator getDataIterator(long address) {
                  return new DataIterator(log, address);
              }
          };
      }
docs: Tries to load meta tree located at specified rootAddress.
  
  @param rootAddress tree root address.
  @return tree instance or null if the address is not valid.