@Test
public void multipleHeaders() throws Exception {

  final Header header = BatchParserCommon.consumeHeaders(toLineList(
      "Content-Id: 1" + CRLF,
      "Content-Id: 2" + CRLF,
      "content-type: Application/http" + CRLF,
      "content-transfer-encoding: Binary" + CRLF));
  assertNotNull(header);
  final List<String> contentIdHeaders = header.getHeaders(HttpHeader.CONTENT_ID);
  assertNotNull(contentIdHeaders);
  assertEquals(2, contentIdHeaders.size());
  assertEquals("1", contentIdHeaders.get(0));
  assertEquals("2", contentIdHeaders.get(1));
}