#!/bin/bash

declare -A UsersRestrictions
UsersRestrictions['root']=""


if [[ -z "${UsersRestrictions['root']}" ]] ; then
    echo root null
else 
    echo root not null
fi

if [[ -z "${UsersRestrictions['notset']}" && "${UsersRestrictions['notset']+x}" ]]; then
    echo notset null
else 
    echo notset not null
fi