code: protected void appendDetail(StringBuilder buffer, String fieldName, Map<?, ?> map) {
          buffer.append(map);
      }
docs: <p>Append to the <code>toString</code> a <code>Map<code>.</p>
  
  @param buffer    the <code>StringBuilder</code> to populate
  @param fieldName the field name, typically not used as already appended
  @param map       the <code>Map</code> to add to the <code>toString</code>,
  not <code>null</code>