code: private byte[] getAsByteArray(String template) throws IOException {
          if (isTemplateGivenAsAnAbsoluteFile(template)) {
              throw new IllegalArgumentException("Template " + template + " should not be given as an absolute file");
          }
          if (!containsTemplate(template)) {
              throw new IllegalArgumentException("Template " + template + " is not a template");
          }
          java.io.InputStream is = null;
          try {
              is = new FileInputStream(getAbsoluteTemplate(template));
              return toByteArray(is);
          } finally {
              closeQuietly(is);
          }
      }
docs: Extract a template from the jar as a byte array