Encoder
A type that can encode values into a native format for external representation.
protocol EncoderRequirements
var codingPath: [CodingKey]The path of coding keys taken to get to this point in encoding.
var userInfo: [CodingUserInfoKey : Any]Any contextual information set by the user for encoding.
func container<Key>(keyedBy: Key.Type) -> KeyedEncodingContainer<Key> Returns an encoding container appropriate for holding multiple values keyed by the given key type.
func singleValueContainer() -> SingleValueEncodingContainer Returns an encoding container appropriate for holding a single primitive value.
func unkeyedContainer() -> UnkeyedEncodingContainer Returns an encoding container appropriate for holding multiple unkeyed values.