code: private static String readClasspathResource(String filename) {
          InputStream is = CreateEntities.class.getResourceAsStream(filename);
          if (is == null) {
              throw new IllegalArgumentException(
                      "Could not find the given file '" + filename + "' in the classpath.");
          }
          
          return readContents(is);
      }
docs: <p>Reads an entire file from the classpath using UTF-8 encoding.</p>
  @param filename the name of the file in the classpath
  @return the contents of the file