     mutating func encode(_ value: Float, forKey key: Key) throws { encode(value, key.stringValue) }
     mutating func encode(_ value: Double, forKey key: Key) throws { encode(value, key.stringValue) }
     mutating func encode(_ value: String, forKey key: Key) throws { encode(value, key.stringValue) }
-    mutating func encodeNil(forKey key: Key) throws { encode(nil, key.stringValue) }
 
     /// Encodes the given value for the given key.
     ///

            try value.encode(to: PersistableEncoder(codingPath: [key], encode: encode))
        }
    }
    
    /// Stores a keyed encoding container for the given key and returns it.
    ///

                try! self.encode(to: encoder)
            }
        }
        encode { (value, key) in
            container[key] = value
        }
    }
}
