protected ACCOUNT loadAccount(
      final Address address, final Function<PathBasedValue<ACCOUNT>, ACCOUNT> accountFunction) {
    try {
      final PathBasedValue<ACCOUNT> pathBasedValue = accountsToUpdate.get(address);
      if (pathBasedValue == null) {
        final Account account;
        if (wrappedWorldView() instanceof PathBasedWorldStateUpdateAccumulator) {
          final PathBasedWorldStateUpdateAccumulator<ACCOUNT> worldStateUpdateAccumulator =
              (PathBasedWorldStateUpdateAccumulator<ACCOUNT>) wrappedWorldView();
          account = worldStateUpdateAccumulator.loadAccount(address, accountFunction);
        } else {
          account = wrappedWorldView().get(address);
        }
        if (account instanceof PathBasedAccount pathBasedAccount) {
          ACCOUNT mutableAccount = copyAccount((ACCOUNT) pathBasedAccount, this, true);
          accountsToUpdate.put(
              address, new PathBasedValue<>((ACCOUNT) pathBasedAccount, mutableAccount));
          return mutableAccount;
        } else {
          // add the empty read in accountsToUpdate
          accountsToUpdate.put(address, new PathBasedValue<>(null, null));
          return null;
        }
      } else {
        return accountFunction.apply(pathBasedValue);
      }
    } catch (MerkleTrieException e) {
      // need to throw to trigger the heal
      throw new MerkleTrieException(
          e.getMessage(), Optional.of(address), e.getHash(), e.getLocation());
    }
  }
Imports unchanged state data from an external source into the current state. This method
focuses on integrating state data from the specified source that has been read but not
modified.

<p>The method ensures that only new, unmodified data from the source is added to the current
state. If a state data has already been read or modified in the current state, it will not be
added again to avoid overwriting any existing modifications.

@param source The source accumulator
ethereum/core/src/main/java/org/hyperledger/besu/ethereum/trie/pathbased/common/worldview/accumulator/PathBasedWorldStateUpdateAccumulator.java