Edit hashforether.sol

solidity_examples/hashforether.sol

@@ -3,9 +3,9 @@ pragma solidity 0.5.0;
 
 contract HashForEther {
 
-    function withdrawWinnings() public {
+    function withdrawWinnings() public payable {
         // Winner if the last 8 hex characters of the address are 0.
-        require(uint32(msg.sender) == 0);
+        if (uint32(msg.sender) == 0)
             _sendWinnings();
     }