Test that error message is correctly thrown

Author: penelopeysm

test/logdensityproblems.jl

@@ -22,6 +22,11 @@
         @test model.logdensity === ℓ
 
         @test_throws ArgumentError AbstractMCMC.LogDensityModel(mylogdensity)
+
+        @test_throws MethodError LogDensityProblems.capabilities(model)
+        @test_throws "is a wrapper" LogDensityProblems.capabilities(model)
+        @test_throws MethodError LogDensityProblems.logdensity(model, ones(10))
+        @test_throws "is a wrapper" LogDensityProblems.logdensity(model, ones(10))
     end
 
     @testset "fallback for log densities" begin