class ActionView::Template::Handlers::ERB

def valid_encoding(string, encoding)
  # If a magic encoding comment was found, tag the
  # String with this encoding. This is for a case
  # where the original String was assumed to be,
  # for instance, UTF-8, but a magic comment
  # proved otherwise
  string.force_encoding(encoding) if encoding
  # If the String is valid, return the encoding we found
  return string.encoding if string.valid_encoding?
  # Otherwise, raise an exception
  raise WrongEncodingError.new(string, string.encoding)
end