public function testOneDuplicateFieldDetected()
 {
     $fieldsA = array('dup', 'b', 'c');
     $fieldsB = array('dup', 'e');
     $pivot = new PivotDescription($this->dataTable);
     $this->setExpectedException('\\Vube\\GoogleVisualization\\DataSource\\Query\\Exception\\DuplicateFieldException', 'Duplicate fields specified as both A and B: dup, dup');
     $pivot->verifyNoDuplicateFields($fieldsA, $fieldsB, 'A', 'B');
 }