code: public JBBPTextWriter AddExtras(final Extra... extras) {
      JBBPUtils.assertNotNull(extras, "Extras must not be null");
      for (final Extra e : extras) {
        JBBPUtils.assertNotNull(e, "Extras must not be null");
        this.extras.add(0, e);
      }
      return this;
    }
docs: Add extras to context.
  
  @param extras extras to be added to context, must not be null
  @return the context