private static Reader readerFromOther(URL resourceUrl) throws IOException {
    return new InputStreamReader(resourceUrl.openStream(), UTF_8);
  }
Returns the result of substituting the variables defined by the fields of this class (a
concrete subclass of TemplateVars) into the template returned by {@link #parsedTemplate()}.
value/src/main/java/com/google/auto/value/processor/TemplateVars.java