New FIXME.

src/api.js

@@ -204,6 +204,8 @@ export default class Api {
       throw new MethodNotFound(name)
     }
 
+    // FIXME: it can cause issues if there any property assignments in
+    // XO methods called from the API.
     const context = Object.create(this.context)
     context.api = this // Used by system.*().
     context.session = session

src/index.js

@@ -384,6 +384,8 @@ const apiHelpers = {
 }
 
 const setUpApi = (webSocketServer, xo) => {
+  // FIXME: it can cause issues if there any property assignments in
+  // XO methods called from the API.
   const context = { __proto__: xo, ...apiHelpers }
 
   const api = new Api({