package mypkg_test import ( "testing" "github.com/juju/testing" ) func TestMyFunction(t *testing.T) { stub := &testing.Stub{} // Set up the stub's behavior stub.GetReturns(42, nil) // Pass the stub to our function under test result, err := mypkg.MyFunction(stub) // Check the result if result != 42 { t.Errorf("Expected result to be 42, got %d", result) } // Check the error if err != nil { t.Errorf("Expected error to be nil, got %s", err) } // Check that the stub's Get method was called if !stub.GetCalled() { t.Error("Expected Get to be called, but it wasn't") } }This code example demonstrates how to use the Stub type to test a function that depends on an external dependency (in this case, a hypothetical `Get` method). The `GetReturns` method is used to set up the stub to return a specific value and error when its `Get` method is called. The `GetCalled` method is used to verify that the function under test actually called the stub's `Get` method.