@Test
 public void testExtractMessageAllowedEmailCollectionFrom() {
   List<Member> members = new ArrayList<Member>();
   Member member = new Member();
   member.setIsAllowedGoogleTalk(true);
   member.setEmail("*****@*****.**");
   members.add(member);
   member = new Member();
   member.setIsAllowedGoogleTalk(false);
   member.setEmail("*****@*****.**");
   members.add(member);
   member = new Member();
   member.setIsAllowedGoogleTalk(true);
   member.setEmail("whiteship20om");
   members.add(member);
   Collection<String> mails = EmailExtractUtil.extractMessageAllowedEmailCollectionFrom(members);
   assertThat(mails.size(), is(1));
 }