code: @CanIgnoreReturnValue // some processors won't return a useful result
    public static <T> T readBytes(File file, ByteProcessor<T> processor) throws IOException {
      return asByteSource(file).read(processor);
    }
docs: Process the bytes of a file.
  
  <p>(If this seems too complicated, maybe you're looking for {@link #toByteArray}.)
  
  @param file the file to read
  @param processor the object to which the bytes of the file are passed.
  @return the result of the byte processor
  @throws IOException if an I/O error occurs