Type assertion and type switch are commonly used in Go when dealing with _______ interfaces.

Type assertion and type switch are often employed when working with interfaces in Go, especially with concrete interfaces. A concrete interface specifies the exact methods a type must have to satisfy the interface, enabling type assertion to convert the interface back to its concrete type safely. Type switch allows conditional branching based on the concrete type of an interface variable, facilitating efficient and concise code when handling various implementations of an interface. Understanding these mechanisms is essential for effective interface utilization in Go.