|contentLength||The value of the received
Callback, invoked with a
Content-Length header is received.
This callback is invoked on the main thread.
Note: This callback is only called if a
Content-Length header is received. If the remote server does not transmit a
Content-Length header, but does include body data, then it is possible for ReceiveData to be invoked without receiving a call to this method.
Note: This callback may be invoked more than once. An example scenario would be a case where a redirect is encountered, followed by a standard response. If both the redirect and standard response include
Content-Length headers, this method will be invoked twice.