public function testcreate_export_query()
 {
     $emailMan = new EmailMan();
     //test with empty string params
     $expected = 'SELECT emailman.* FROM emailman where ( emailman.deleted IS NULL OR emailman.deleted=0 )';
     $actual = $emailMan->create_export_query('', '');
     $this->assertSame($expected, $actual);
     //test with valid string params
     $expected = 'SELECT emailman.* FROM emailman where (emailman.user_id="") AND ( emailman.deleted IS NULL OR emailman.deleted=0 )';
     $actual = $emailMan->create_export_query('emailman.id', 'emailman.user_id=""');
     $this->assertSame($expected, $actual);
 }