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