code: @Beta
    public static void copy(File from, File to) throws IOException {
      checkArgument(!from.equals(to), "Source %s and destination %s must be different", from, to);
      asByteSource(from).copyTo(asByteSink(to));
    }
docs: Copies all the bytes from one file to another.
  
  <p>Copying is not an atomic operation - in the case of an I/O error, power loss, process
  termination, or other problems, {@code to} may not be a complete copy of {@code from}. If you
  need to guard against those conditions, you should employ other file-level synchronization.
  
  <p><b>Warning:</b> If {@code to} represents an existing file, that file will be overwritten
  with the contents of {@code from}. If {@code to} and {@code from} refer to the <i>same</i>
  file, the contents of that file will be deleted.
  
  <p><b>{@link java.nio.file.Path} equivalent:</b> {@link
  java.nio.file.Files#copy(java.nio.file.Path, java.nio.file.Path, java.nio.file.CopyOption...)}.
  
  @param from the source file
  @param to the destination file
  @throws IOException if an I/O error occurs
  @throws IllegalArgumentException if {@code from.equals(to)}