v3.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract MyContract {
    // State variables
    uint256 private myVariable;
    address private owner;

    // Events
    event ValueChanged(address indexed owner, uint256 indexed newValue);

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

    // Modifiers
    modifier onlyOwner() {
        require(msg.sender == owner, "Not the contract owner");
        _;
    }

    // Functions

    /// @notice Sets a new value for myVariable
    /// @param newValue The new value to be set
    function setValue(uint256 newValue) external onlyOwner {
        require(newValue != myVariable, "New value must be different");
        
        myVariable = newValue;
        emit ValueChanged(msg.sender, newValue);
    }

    /// @notice Retrieves the current value of myVariable
    /// @return The current value of myVariable
    function getValue() external view returns (uint256) {
        return myVariable;
    }

    /// @notice Retrieves the address of the contract owner
    /// @return The address of the contract owner
    function getOwner() external view returns (address) {
        return owner;
    }

    /// @notice Transfers ownership of the contract to a new address
    /// @param newOwner The address of the new owner
    function transferOwnership(address newOwner) external onlyOwner {
        require(newOwner != address(0), "Invalid new owner address");
        require(newOwner != owner, "New owner is the same as the current owner");

        owner = newOwner;
    }

    /// @notice Allows the contract owner to withdraw any accidentally sent Ether
    function withdrawEther() external onlyOwner {
        payable(owner).transfer(address(this).balance);
    }

    /// @dev Fallback function to reject any Ether sent to the contract
    receive() external payable {
        revert("Contract does not accept Ether");
    }
}