WebSocketError.needMoreInput

[zxpLearnios]

when I use it from the guide in github. but it show "

func readResponse() throws {
let end : [UInt8] = [ 0x0D, 0x0A, 0x0D, 0x0A ]
let ptr = memmem(inputBytes!+inputBytesStart, inputBytesLength, end, 4)
if ptr == nil {
throw WebSocketError.needMoreInput
}
"
throw WebSocketError.needMoreInput is throw