Please help to fill in the detail of the below code:

import socket

from vending$\_$machine import VendingMachine

class Server:

def $\_\_$init$\_\_($self$,$ products$\_$file, transactions$\_$file$)$:

self.vending$\_$machine $=$ VendingMachine$($products$\_$file, transactions$\_$file$)$

def start$\_$server$($self$)$:

# Start server and listen for client connections

pass

def handle$\_$client$\_$connection$($self$,$ client$\_$socket$)$:

# Handle client requests and update vending machine

pass

import socket

from vending$\_$machine import VendingMachine

class Client:

def $\_\_$init$\_\_($self$,$ server$\_$address$)$:

self.server$\_$address $=$ server$\_$address

self.vending$\_$machine $=$ None

def connect$\_$to$\_$server$($self$)$:

# Connect to server and get initial product list

pass

def display$\_$menu$($self$)$:

# Display available products and options

pass

def get$\_$user$\_$input$($self$)$:

# Get user input for product selection and quantity

pass

def send$\_$transaction$($self$,$ products$\_$and$\_$quantities$)$:

# Send transaction to server

pass

def receive$\_$updated$\_$products$($self$)$:

# Receive updated product list from server

pass

from product import Product, Snack, Drink

class VendingMachine:

def $\_\_$init$\_\_($self$,$ products$\_$file, transactions$\_$file$)$:

self.products $=$ self.load$\_$products$($products$\_$file$)$

self.transactions $=$ self.load$\_$transactions$($transactions$\_$file$)$

def load$\_$products$($self$,$ products$\_$file$)$:

# Load products from file

pass

def load$\_$transactions$($self$,$ transactions$\_$file$)$:

# Load transactions from file

pass

def display$\_$products$($self$)$:

# Display available products

pass

def add$\_$product$($self$,$ product$\_$id$,$ quantity$)$:

# Add product to the vending machine

pass

def remove$\_$product$($self$,$ product$\_$id$,$ quantity$)$:

# Remove product from the vending machine

pass

def calculate$\_$total$($self$,$ products$\_$and$\_$quantities$)$:

# Calculate total cost of products

pass

def process$\_$payment$($self$,$ total$\_$amount, payment$\_$method$)$:

# Process payment and return change if applicable

pass

def complete$\_$transaction$($self$,$ products$\_$and$\_$quantities$)$:

# Update product stock and save transaction

pass