public static String join(List<PdlParser.IdentifierContext> identifiers)
  {
    StringBuilder stringBuilder = new StringBuilder();
    Iterator<PdlParser.IdentifierContext> iter = identifiers.iterator();
    while (iter.hasNext())
    {
      stringBuilder.append(iter.next().value);
      if (iter.hasNext())
      {
        stringBuilder.append(".");
      }
    }
    return stringBuilder.toString();
  }
@Test
  public void testJoin()
  {
    PdlParser.IdentifierContext a = new PdlParser.IdentifierContext(null, 0);
    a.value  = "a";
    PdlParser.IdentifierContext b = new PdlParser.IdentifierContext(null, 0);
    b.value  = "b";

    assertEquals(PdlParseUtils.join(Arrays.asList(a, b)), "a.b");
  }