Have added the required client, server, proto and proto generated files.
The design of the example is as follows:
1. The client sends a bulk amount of data(approx. 2 KB in each
iteration) to the server in a streaming call.
2. The server applies back-pressure by delaying reading of the requests,
which makes the client pause sending requests after around 64KB
3. The client then resumes sending requests only after the server reads
a few requests and clears the buffer.
By adding print statements on data send/receive on both client and
server side, the client pausing/resuming requests can be seen clearly.
The client and server logs can be seen below:
**Client Logs**
```
Request 10: Sent 20000 bytes in total
Request 20: Sent 40000 bytes in total
Request 30: Sent 60000 bytes in total
Request 40: Sent 80000 bytes in total
Received 10 responses
Request 50: Sent 100000 bytes in total
Received 20 responses
Request 60: Sent 120000 bytes in total
Received 30 responses
Request 70: Sent 140000 bytes in total
Received 40 responses
Request 80: Sent 160000 bytes in total
Received 50 responses
Request 90: Sent 180000 bytes in total
Received 60 responses
Request 100: Sent 200000 bytes in total
Received 70 responses
Received 80 responses
Received 90 responses
Received 100 responses
```
**Server Logs**
```
Server started, listening on 50051
Request 10: Received 20000 bytes in total
Request 10: Sent 20000 bytes in total
Request 20: Received 40000 bytes in total
Request 20: Sent 40000 bytes in total
Request 30: Received 60000 bytes in total
Request 30: Sent 60000 bytes in total
Request 40: Received 80000 bytes in total
Request 40: Sent 80000 bytes in total
Request 50: Received 100000 bytes in total
Request 50: Sent 100000 bytes in total
Request 60: Received 120000 bytes in total
Request 60: Sent 120000 bytes in total
Request 70: Received 140000 bytes in total
Request 70: Sent 140000 bytes in total
Request 80: Received 160000 bytes in total
Request 80: Sent 160000 bytes in total
Request 90: Received 180000 bytes in total
Request 90: Sent 180000 bytes in total
Request 100: Received 200000 bytes in total
Request 100: Sent 200000 bytes in total
```