Pinq\Analysis\ITypeAnalysis::getReturnTypeOf PHP Method

    public function getReturnTypeOf(O\Expression $expression);

 protected function assertTypeMatchesValue(ITypeAnalysis $analysis, O\Expression $expression, IType $metadataType = null)
 {
     $type = $this->typeSystem->getTypeFromValue($expression->evaluate(O\EvaluationContext::staticContext(__NAMESPACE__, __CLASS__)));
     $this->assertEqualTypes($type, $analysis->getReturnTypeOf($expression));
     if ($metadataType !== null) {
         $this->assertEqualTypes($metadataType, $type, $expression->compileDebug());
     }
 }