Support ERC173

contracts/access/IERC173.sol

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.0;
+
+/**
+ * @dev Interface of the ERC173 standard, as defined in the
+ * https://eips.ethereum.org/EIPS/eip-173[EIP].
+ *
+ * For an implementation, see {Ownable}.
+ */
+interface IERC173 {
+    /**
+     * @dev Emitted when ownership of a contract changes.
+     */
+    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
+
+    /**
+     * @notice Returns the address of the owner.
+     * @return The address of the owner.
+     */
+    function owner() external view returns (address);
+
+    /**
+     * @notice Set the address of the new owner of the contract.
+     * @dev Set newOwner to address(0) to renounce any ownership.
+     * @param newOwner The address of the new owner of the contract.
+     */
+    function transferOwnership(address newOwner) external;
+}

contracts/access/Ownable.sol

@@ -2,6 +2,7 @@
 
 pragma solidity ^0.8.0;
 
+import "./IERC173.sol";
 import "../utils/Context.sol";
 
 /**
@@ -16,11 +17,9 @@ import "../utils/Context.sol";
  * `onlyOwner`, which can be applied to your functions to restrict their use to
  * the owner.
  */
-abstract contract Ownable is Context {
+abstract contract Ownable is Context, IERC173 {
     address private _owner;
 
-    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
-
     /**
      * @dev Initializes the contract setting the deployer as the initial owner.
      */
@@ -31,7 +30,7 @@ abstract contract Ownable is Context {
     /**
      * @dev Returns the address of the current owner.
      */
-    function owner() public view virtual returns (address) {
+    function owner() public view virtual override returns (address) {
         return _owner;
     }
 
@@ -58,7 +57,7 @@ abstract contract Ownable is Context {
      * @dev Transfers ownership of the contract to a new account (`newOwner`).
      * Can only be called by the current owner.
      */
-    function transferOwnership(address newOwner) public virtual onlyOwner {
+    function transferOwnership(address newOwner) public virtual override onlyOwner {
         require(newOwner != address(0), "Ownable: new owner is the zero address");
         _transferOwnership(newOwner);
     }