Install Docker In Debian 9 (Stretch)

install-docker-deb9.sh

#!/bin/bash
#
# -----------------------
#
# This is a script that installs docker-ce (Docker Community Edition) on Debian 9
# Inspired by https://gist.github.com/frgomes/a6f889583860f5b330c06c8b46fa0f42
#
# -----------------------

# Pre-requesite
sudo apt-get -y remove docker docker-engine docker.io

# Docker Setup (repo)
sudo apt-get update
sudo apt-get install -y apt-transport-https ca-certificates wget software-properties-common
wget https://download.docker.com/linux/debian/gpg 
sudo apt-key add gpg
echo "deb [arch=amd64] https://download.docker.com/linux/debian $(lsb_release -cs) stable" | sudo tee -a /etc/apt/sources.list.d/docker.list
sudo apt-get update
sudo apt-cache policy docker-ce

# Install Docker
sudo apt-get -y install docker-ce

# Start Docker
sudo systemctl start docker

# Enable Docker service on boot
sudo systemctl enable docker

# Create a group "docker"
sudo groupadd docker

# Add user to group "docker"
sudo gpasswd -a $USER docker

# Restart Docker
sudo systemctl restart docker

could you please add "newgrp docker" at the end of the script to refresh user permission on the group