Prevent rpc endpoints from being overridden

Signed-off-by: Antony Denyer <git@antonydenyer.co.uk>

Author: antonydenyer

besu/src/main/java/org/hyperledger/besu/RunnerBuilder.java

@@ -863,7 +863,15 @@ private Map<String, JsonRpcMethod> jsonRpcMethods(
                 dataDir,
                 besuController.getProtocolManager().ethContext().getEthPeers());
     methods.putAll(besuController.getAdditionalJsonRpcMethods(jsonRpcApis));
-    methods.putAll(rpcEndpointServiceImpl.getPluginMethods(jsonRpcConfiguration.getRpcApis()));
+
+    var pluginMethods = rpcEndpointServiceImpl.getPluginMethods(jsonRpcConfiguration.getRpcApis());
+
+    var overriddenMethods = methods.keySet().stream().filter(pluginMethods::containsKey).collect(Collectors.toList());
+    if(overriddenMethods.size() > 0){
+      throw new RuntimeException("You can not override built in methods " + overriddenMethods);
+    }
+
+    methods.putAll(pluginMethods);
     return methods;
   }