Accept interfaces return structs

Go interfaces cannot return structs directly because an interface is a type, not a value; instead, define a function that returns the interface type and assign a struct value to it.

type MyInterface interface {
    DoSomething()
}

type MyStruct struct{}

func (m MyStruct) DoSomething() {}

func GetInterface() MyInterface {
    return MyStruct{}
}

The function GetInterface returns the interface type MyInterface, which holds the concrete MyStruct value.

An interface is like a contract that defines what actions a value can perform, not the value itself. You cannot return the contract directly; you must return a specific item (a struct) that fulfills that contract. Think of it like ordering a "drink" (interface) and receiving a "coffee" (struct) that satisfies the order.