Small extension to use try-catch error handling in SwiftyJSON

SwiftyJSON+try.swift

import Foundation

public enum JSONError: Int, ErrorType {
    case UnsupportedType = 999
    case IndexOutOfBounds = 900
    case WrongType = 901
    case ErrorNotExist = 500
}

public extension JSON {
    
    public func tryGet<T>(@autoclosure f: () -> T?) throws -> T {
        guard let value = f() else {
            throw JSONError.WrongType
        }
        return value
    }
    
    public func tryBool() throws -> Bool {
        return try self.tryGet(self.bool)
    }
    
    public func tryString() throws -> String {
        return try self.tryGet(self.string)
    }
    
    public func tryNumber() throws -> NSNumber {
        return try self.tryGet(self.number)
    }
    
    public func tryURL() throws -> NSURL {
        return try self.tryGet(self.URL)
    }
    
    public func tryDouble() throws -> Double {
        return try self.tryGet(self.double)
    }
    
    public func tryFloat() throws -> Float {
        return try self.tryGet(self.float)
    }
    
    public func tryInt() throws -> Int {
        return try self.tryGet(self.int)
    }
    
    public func tryUInt() throws -> UInt {
        return try self.tryGet(self.uInt)
    }
    
    public func tryInt64() throws -> Int64 {
        return try self.tryGet(self.int64)
    }
    
    public func tryUInt64() throws -> UInt64 {
        return try self.tryGet(self.uInt64)
    }
    
}

Nice :)
Can you provide a little example on how to use it?
Thank you.