Responds with the allowed HTTP methods for this server in the Allow header.
The body of the response is empty.

HTTP Method:

• OPTIONS

Responses:

• 204 No Content: Returns an empty body with the Allow header set to
  “GET, POST, PUT, PATCH, DELETE, OPTIONS, HEAD”.

Echoes back the request’s method, headers, and the parsed JSON body.
Expects a JSON request body.

HTTP Method:

• PATCH

Request Body:

• Payload: A generic JSON object.

Responses:

• 200 OK: Returns a JSON object containing method, headers, and parsed body.
• 400 Bad Request: If the request body is not valid JSON.

Echoes back the request’s method, headers, and the parsed JSON body.
Expects a JSON request body.

HTTP Method:

• POST

Request Body:

• Payload: A generic JSON object.

Responses:

• 200 OK: Returns a JSON object containing method, headers, and parsed body.
• 400 Bad Request: If the request body is not valid JSON.

Echoes back the request’s method, headers, and the parsed JSON body.
Expects a JSON request body.

HTTP Method:

• PUT

Request Body:

• Payload: A generic JSON object.

Responses:

• 200 OK: Returns a JSON object containing method, headers, and parsed body.
• 400 Bad Request: If the request body is not valid JSON.

This handler allows testing of how a client handles different HTTP status codes.
It accepts any HTTP method.

Path Parameters:

• code: The HTTP status code to return (e.g., 200, 404, 500).

Responses:

• Returns the status code specified by the code path parameter.
• If an invalid code is provided (e.g., not a number or out of valid range),
  it defaults to 400 Bad Request.