How to spec a java object in a function schema?

[Tillaert]

Is there a way to write a funciton schema that checks for a java type?

eg.

(defn f [a b c]
{:malli/schem [:=> [:cat ??? :int :string] :int]})

Where ??? checks whether an object of the type org.hyperledger.fabric.shim.ChaincodeStub ?

[ikitommi]

For just validation, you can use :fn, which takes any predicate function, e.g. [:fn (partial instance? org.hyperledger.fabric.shim.ChaincodeStub)].