I m trying to Create a product Grid in My custom Module Admin Form

[waqasbutt]

am trying to add a product Grid in My custom Module i searched a internet and found this Solution Magento 2 :

https://magento.stackexchange.com/questions/105036/magento-2-how-to-add-product-grid-in-custom-modul...

Now there is a function in this example names as SetInProducts,

i m getting error

Spoiler

Call to a member function setInProducts() on Boolean

I searched in Whole Module to found Definition of this function but haven't got any solution if anyone have a better solution please Guide me

NOTE

Spoiler

I am using Block to create the admin form