Pinq\IQueryable::keys PHP Method

    public function keys();

 public function testRemovesCorrectSavedResults()
 {
     $this->queryResultsCollection->saveResults($takeExpression = $this->queryable->take(1)->getExpression(), ['take']);
     $this->queryResultsCollection->saveResults($keysExpression = $this->queryable->keys()->getExpression(), ['keys']);
     $this->assertComputesResult($takeExpression, ['take']);
     $this->assertComputesResult($keysExpression, ['keys']);
     $this->queryResultsCollection->removeResults($keysExpression);
     $this->assertComputesResult($takeExpression, ['take']);
     $this->assertCannotComputesResult($keysExpression);
     $this->queryResultsCollection->removeResults($takeExpression);
     $this->assertCannotComputesResult($takeExpression);
 }