code: public static int copy( File sourceFileOrDirectory,
                              File destinationFileOrDirectory ) throws IOException {
          return copy(sourceFileOrDirectory, destinationFileOrDirectory, null);
      }
docs: Copy the source file system structure into the supplied target location. If the source is a file, the destination will be
  created as a file; if the source is a directory, the destination will be created as a directory.
  
  @param sourceFileOrDirectory the file or directory whose contents are to be copied into the target location
  @param destinationFileOrDirectory the location where the copy is to be placed; does not need to exist, but if it does its
  type must match that of <code>src</code>
  @return the number of files (not directories) that were copied
  @throws IllegalArgumentException if the <code>src</code> or <code>dest</code> references are null
  @throws IOException