/**
  * Tests the guessContactIdsBySubscribers method.
  *
  */
 public function testGuessContactIdsBySubscribers()
 {
     // Create empty tables.
     CRM_Mailchimp_Sync::createTemporaryTableForMailchimp();
     CRM_Mailchimp_Sync::createTemporaryTableForCiviCRM();
     CRM_Core_DAO::executeQuery("INSERT INTO tmp_mailchimp_push_c (email, contact_id) VALUES\n      ('*****@*****.**', 1),\n      ('*****@*****.**', 2);");
     CRM_Core_DAO::executeQuery("INSERT INTO tmp_mailchimp_push_m (email) VALUES\n      ('*****@*****.**'),\n      ('*****@*****.**');");
     // Check for a match.
     $matched = CRM_Mailchimp_Sync::guessContactIdsBySubscribers();
     $this->assertEquals(1, $matched);
     // Check the matched record did indeed match.
     $result = CRM_Core_DAO::singleValueQuery('SELECT COUNT(*) c FROM tmp_mailchimp_push_m WHERE email = "*****@*****.**" AND cid_guess = 1');
     $this->assertEquals(1, $result);
     // Check the other one did not.
     $result = CRM_Core_DAO::singleValueQuery('SELECT COUNT(*) c FROM tmp_mailchimp_push_m WHERE email = "*****@*****.**" AND cid_guess IS NULL');
     $this->assertEquals(1, $result);
     CRM_Mailchimp_Sync::dropTemporaryTables();
 }