@Override
    public void onConnected() throws IOException {
        if (mCallback != null) {
            mCallback.onConnected();
        }
    }
Read data from remote server and put it into the given buffer.

@param buffer A buffer to store data.
@return The read length.
@throws IOException if an I/O error occurs.
netbare-core/src/main/java/com/github/megatronking/netbare/tunnel/NioTunnel.java