code: public void render(final Writer writer) throws GitChangelogRepositoryException {
      final MustacheFactory mf = new DefaultMustacheFactory();
      final String templateContent = checkNotNull(getTemplateContent(), "No template!");
      final StringReader reader = new StringReader(templateContent);
      final Mustache mustache = mf.compile(reader, this.settings.getTemplatePath());
      try {
        final boolean useIntegrationIfConfigured = shouldUseIntegrationIfConfigured(templateContent);
        final Changelog changelog = this.getChangelog(useIntegrationIfConfigured);
        mustache
            .execute(
                writer, //
                new Object[] {changelog, this.settings.getExtendedVariables()} //
                )
            .flush();
      } catch (final IOException e) {
        // Should be impossible!
        throw new GitChangelogRepositoryException("", e);
      }
    }
docs: Get the changelog.
  
  @throws GitChangelogRepositoryException