 			|| ( cc >= 123 && cc <= 126 )
 			|| self == 43 )
 	}
-    
+
     // same as String(self, radix: 16)
     // but outputs two characters. i.e. 0 padded
 	var hexString: String {

		uuid_generate_random(u)
		self.uuid = UUID.uuidFromPointer(u)
	}
	
	public init(_ string: String) {
		let u = UnsafeMutablePointer<UInt8>.allocate(capacity:  sizeof(uuid_t.self))
		defer {

    public func sendFile(_ file: File, callBack: (Bool) -> ()) throws {
        try self.sendFd(Int32(file.fd), callBack: callBack)
    }

    /// Receive an existing opened `File` descriptor from the sender
    /// - parameter callBack: The callback to call when the receive completes. The parameter passed will be the received `File` object or nil.
    /// - throws: `PerfectError.NetworkError`
    public func receiveFile(callBack: (File?) -> ()) throws {
        try self.receiveFd {
            fd in

            if fd == invalidSocket {
                callBack(nil)
            } else {
