ownership & killable

src/OwnableExternal.sol

@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)
+
+pragma solidity ^0.8.20;
+
+import "../lib/openzeppelin-contracts/contracts/utils/Context.sol";
+import {OwnableInternal} from "./OwnableInternal.sol";
+import {IOwnable} from "./IOwnable.sol";
+
+/**
+ * @dev Contract module which provides a basic access control mechanism, where
+ * there is an account (an owner) that can be granted exclusive access to
+ * specific functions.
+ *
+ * The initial owner is set to the address provided by the deployer. This can
+ * later be changed with {transferOwnership}.
+ *
+ * This module is used through inheritance. It will make available the modifier
+ * `onlyOwner`, which can be applied to your functions to restrict their use to
+ * the owner.
+ */
+abstract contract OwnableExternal is OwnableInternal, IOwnable {
+    /**
+     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
+     */
+    constructor(address initialOwner) {
+        if (initialOwner == address(0)) {
+            revert OwnableInvalidOwner(address(0));
+        }
+        _transferOwnership(initialOwner);
+    }
+
+    /**
+     * @dev Returns the address of the current owner.
+     */
+    function owner() external view virtual returns (address) {
+        return _owner;
+    }
+
+    /**
+     * @dev Leaves the contract without owner. It will not be possible to call
+     * `onlyOwner` functions. Can only be called by the current owner.
+     *
+     * NOTE: Renouncing ownership will leave the contract without an owner,
+     * thereby disabling any functionality that is only available to the owner.
+     */
+    function renounceOwnership() external virtual onlyOwner {
+        _transferOwnership(address(0));
+    }
+
+    /**
+     * @dev Transfers ownership of the contract to a new account (`newOwner`).
+     * Can only be called by the current owner.
+     */
+    function transferOwnership(address newOwner) external virtual onlyOwner {
+        if (newOwner == address(0)) {
+            revert OwnableInvalidOwner(address(0));
+        }
+        _transferOwnership(newOwner);
+    }
+
+}