4. implement Record<K, V>

Record<K, V> returns an object type with keys of K and values of V.

Please implement MyRecord<K, V> by yourself.

Notice that property key could only be number | string | symbol.

type Key = 'a' | 'b' | 'c'const a: Record<Key, string> = {  a: 'BFE.dev',  b: 'BFE.dev',  c: 'BFE.dev'}a.a = 'bigfrontend.dev' // OKa.b = 123 // Errora.d = 'BFE.dev' // Errortype Foo = MyRecord<{a: string}, string> // Error