HandyJSON数组转String, 编译器一直报错

public class Program: HandyJSON {
public var id: String!
public var name: String!
public var xml: String!
public var programPath: String!

public required init() {}

public init(id: String, name: String, xml: String, programPath: String) {
self.id = id
self.name = name
self.xml = xml
self.programPath = programPath
}
}

let jsons = [Program]()
let jsonString = jsons.toJSONString()

Use the Program example and the jsons.toJSONString() call as the reproduction, then inspect the compiler diagnostic in the attached screenshot and the array-serialization entry point. Done means the example compiles and produces a JSON string for an empty [Program] array.

Written by the indexing model from the issue text.