Bank.sol

// SPDX-License-Identifier: GPL-3.0

pragma solidity >=0.7.0 <0.9.0;


contract Bank {

    //Properties

    address private owner;

    mapping(address => uint256) public addressToBalance;

    //modifiers
    modifier isOwner() {
        require(msg.sender == owner, "Sender is not owner");
        _;
    }

    //events
    event OwnerChanged(address indexed oldOwner, address indexed newOwner);
    event BalanceIncreased(address indexed target, uint256 value);


    //constructor
    constructor(){ 
        owner = msg.sender;
    }


    //functions
    function addBalance(address to, uint value) public isOwner {
        addressToBalance[address(to)] = value;
        emit BalanceIncreased(to, value);
    }

}