Fix Python JSON code example (#3159)

packages/react-openapi/src/stringifyOpenAPI.ts

@@ -1,17 +1,25 @@
 /**
  * Stringify an OpenAPI object. Same API as JSON.stringify.
  */
-export function stringifyOpenAPI(body: unknown, _?: null, indent?: number): string {
+export function stringifyOpenAPI(
+    value: any,
+    replacer?: ((this: any, key: string, value: any) => any) | null,
+    space?: string | number
+): string {
     return JSON.stringify(
-        body,
+        value,
         (key, value) => {
             // Ignore internal keys
             if (key.startsWith('x-gitbook-')) {
                 return undefined;
             }
 
+            if (replacer) {
+                return replacer(key, value);
+            }
+
             return value;
         },
-        indent
+        space
     );
 }