Key Value Store

For this coding problem, we are writing a simple key$-$value store. There are two files $($server$.$py and client.py$)$ and each needs to define two classes Server and Client respectively. The Server class holds a key$-$value store, that can be updated and accessed by the Client class $($who has a Server instance passed into its constructor$).$ Multiple servers can hold different data, but when a Client instance$$s sync$\_$servers method is called, all the servers must consolidate information. If two servers have values stored with the same key, the most recent assignment is preserved.

The Client class must support the following methods:

put, which takes a key and a value. It should store the information in the server.

get, which takes a key. It should return the value that is associated with that key from the server. Return None if not value exists.

sync$\_$servers, which takes no arguments. It should cause all servers to merge their information.

Please implement sync$\_$servers

here are the test cases please ensure that the code passes all the test cases:

import sqlite$3$

import unittest

from pprint import pprint

import sys

import os

sys$.$path.append$("/$home$/$codio$/$workspace$/$student$\_$code$/")$

from client import Client

from server import Server

class TestCheckServerClient$($unittest$.$TestCase$)$:

def test$\_$example$\_$single$\_$client$($self$)$:

s$1=$ Server$()$

c$1=$ Client$($s$1)$

assert c$1.$get$("$hello$")$ is None

c$1.$put$("$hello$",$ "world"$)$

assert c$1.$get$("$hello$")==$ "world"

c$1.$put$("$hello$",$ "WORLD!"$)$

assert c$1.$get$("$hello$")==$ "WORLD!"

def test$\_$example$\_$multiple$\_$clients$($self$)$:

s$1=$ Server$()$

c$1=$ Client$($s$1)$

c$2=$ Client$($s$1)$

assert c$1.$get$("$hello$")$ is None

assert c$2.$get$("$hello$")$ is None

c$1.$put$("$hello$",$ "world"$)$

assert c$1.$get$("$hello$")==$ "world"

assert c$2.$get$("$hello$")==$ "world"

c$3=$ Client$($s$1)$

c$2.$put$("$hello$",$ "WORLD!"$)$

assert c$1.$get$("$hello$")==$ "WORLD!"

assert c$2.$get$("$hello$")==$ "WORLD!"

assert c$3.$get$("$hello$")==$ "WORLD!"

def test$\_$example$\_$multiple$\_$servers$($self$)$:

s$1=$ Server$()$

c$1=$ Client$($s$1)$

c$2=$ Client$($s$1)$

c$1.$put$("$hello$",$ "world"$)$

assert c$1.$get$("$hello$")==$ "world"

assert c$2.$get$("$hello$")==$ "world"

s$2=$ Server$()$

c$3=$ Client$($s$2)$

c$3.$put$("$josh$",$ "nahum"$)$

assert c$3.$get$("$josh$")==$ "nahum"

assert c$1.$get$("$josh$")$ is None

assert c$3.$get$("$hello$")$ is None

c$4=$ Client$($s$2)$

assert c$4.$get$("$josh$")==$ "nahum"

def test$\_$example$\_$server$\_$sync$\_$no$\_$key$\_$overlap$($self$)$:

s$1=$ Server$()$

c$1=$ Client$($s$1)$

c$2=$ Client$($s$1)$

c$1.$put$("$hello$",$ "world"$)$

assert c$1.$get$("$hello$")==$ "world"

assert c$2.$get$("$hello$")==$ "world"

s$2=$ Server$()$

c$3=$ Client$($s$2)$

c$3.$put$("$josh$",$ "nahum"$)$

assert c$3.$get$("$josh$")==$ "nahum"

assert c$1.$get$("$josh$")$ is None

assert c$3.$get$("$hello$")$ is None

c$4=$ Client$($s$2)$

assert c$4.$get$("$josh$")==$ "nahum"

s$3=$ Server$()$

c$5=$ Client$($s$3)$

c$5.$sync$\_$servers$()$

assert c$5.$get$("$josh$")==$ "nahum"

assert c$5.$get$("$hello$")==$ "world"

assert c$3.$get$("$josh$")==$ "nahum"

assert c$3.$get$("$hello$")==$ "world"

assert c$1.$get$("$josh$")==$ "nahum"

assert c$1.$get$("$hello$")==$ "world"

def test$\_$example$\_$server$\_$repeated$\_$keys$($self$)$:

s$1=$ Server$()$

c$1=$ Client$($s$1)$

c$2=$ Client$($s$1)$

c$1.$put$("$hello$",$ "world"$)$

assert c$1.$get$("$hello$")==$ "world"

assert c$2.$get$("$hello$")==$ "world"

c$1.$put$("$ferret$",$ "dany"$)$

s$2=$ Server$()$

c$3=$ Client$($s$2)$

c$3.$put$("$josh$",$ "nahum"$)$

assert c$3.$get$("$josh$")==$ "nahum"

assert c$1.$get$("$josh$")$ is None

assert c$3.$get$("$hello$")$ is None

c$3.$put$("$ferret$",$ "ghost"$)$

c$4=$ Client$($s$2)$

assert c$4.$get$("$josh$")==$ "nahum"

assert c$4.$get$("$ferret$")==$ "ghost"

assert c$1.$get$("$ferret$")==$ "dany"

s$3=$ Server$()$

c$5=$ Client$($s$3)$

c$5.$sync$\_$servers$()$

assert c$5.$get$("$josh$")==$ "nahum"

assert c$5.$get$("$hello$")==$ "world"

assert c$5.$get$("$ferret$")==$ "ghost"

assert c$3.$get$("$josh$")==$ "nahum"

assert c$3.$get$("$hello$")==$ "world"

assert c$3.$get$("$ferret$")==$ "ghost"

assert c$1.$get$("$josh$")==$ "nahum"

assert c$1.$get$("$hello$")==$ "world"

assert c$1.$get$("$ferret$")==$ "ghost"

c$5.$put$("$ferret$",$ "racetrack"$)$

assert c$5.$get$("$ferret$")==$ "racetrack"

assert c$3.$get$("$ferret$")==$ "ghost"

Once again please ensure the sync$\_$server function is implemented and the code passes every test case provided