code: public Set<File> resolveFileList(List<String> objectNames,
              Collection<File> tplFiles) {
  
          // First just copy the named templates.
          Set<File> filesToProcess = new TreeSet<File>();
          if (tplFiles != null) {
              filesToProcess.addAll(tplFiles);
          }
  
          // Now loop over all of the object template names, lookup the files, and
          // add them to the set of files to process.
          if (objectNames != null) {
              for (String oname : objectNames) {
                  SourceFile source = sourceRepository.retrievePanSource(oname);
                  if (!source.isAbsent()) {
                      filesToProcess.add(source.getPath());
                  } else {
                      throw EvaluationException.create((SourceRange) null,
                              (Context) null, MSG_CANNOT_LOCATE_OBJECT_TEMPLATE,
                              oname);
                  }
              }
          }
  
          return Collections.unmodifiableSet(filesToProcess);
      }
docs: Resolve a list of object template names and template Files to a set of
  files based on this instance's include directories.
  
  @param objectNames
  object template names to lookup
  @param tplFiles
  template Files to process
  
  @return unmodifiable set of the resolved file names