/**
  * test grabbing a Unit Of Measure that does not exist
  **/
 public function testGetInvalidUnitOfMeasureByUnitId()
 {
     // grab a unit of measure id that exceeds the maximum allowable unit id
     $unitOfMeasure = UnitOfMeasure::getUnitOfMeasureByUnitId($this->getPDO(), InventoryTextTest::INVALID_KEY);
     $this->assertNull($unitOfMeasure);
 }