package main import ( "fmt" "github.com/goplus/llgo/_demo/issue1370_geometry/geometry" ) func main() { rect := geometry.NewRectangle(5.0, 3.0) err := geometry.RegisterShape(rect, 42) if err != nil { println("FAIL: RegisterShape returned error") return } if rect.GetID() != 42 { println("FAIL: ID not set correctly") return } area := rect.Area() fmt.Printf("Area: %.1f\n", area) if area != 15.0 { println("FAIL: Area calculation incorrect") return } println("SUCCESS: Custom interface with private methods works correctly") }