Enable delivery of chunks to requestor.
@param cb will be called after every read of data with the same argument
as the completion callback. Will never be called on an empty
response. May drain the input buffer; it will be drained
automatically on return.
Enable delivery of chunks to requestor. @param cb will be called after every read of data with the same argument as the completion callback. Will never be called on an empty response. May drain the input buffer; it will be drained automatically on return.