code: private static File[] listFiles(final File srcDir, final FileFilter filter) {
  
          final File[] files;
          if (filter == null) {
              files = srcDir.listFiles();
          } else {
              files = srcDir.listFiles(filter);
          }
          return files;
  
      }
docs: List all files for a directory.
  
  @param srcDir
  Directory to list the files for - Cannot be <code>null</code> and must be a valid directory.
  @param filter
  Filter or <code>null</code> for all files.
  
  @return List of child entries of the directory.