code: protected List<F> getChildFiles(List<String> childNames) throws IOException {
          if (childNames == null) {
              return null;
          }
          List<F> childFiles = new ArrayList<F>(childNames.size());
          for (String childName : childNames) {
              childFiles.add(getChildFile(childName));
          }
          return childFiles;
      }
docs: Conversion method.
  
  @param childNames
  A list of child names.
  @return The list of child files, one for each name.
  @throws IOException