```mermaid
sequenceDiagram
participant browser
participant server
browser->>server: POST https://studies.cs.helsinki.fi/exampleapp/new_note
activate server
server-->>data.jason: Save new note
browser->>server: GET https://studies.cs.helsinki.fi/exampleapp/notes
activate server
server-->>browser: HTML document
deactivate server
browser->>server: GET https://studies.cs.helsinki.fi/exampleapp/main.css
activate server
server-->>browser: the CSS file
deactivate server
browser->>server: GET https://studies.cs.helsinki.fi/exampleapp/main.js
activate server
server-->>browser: the JavaScript file
deactivate server
browser->>server: GET https://studies.cs.helsinki.fi/exampleapp/data.json
activate server
server-->>browser: [{ "content": "HTML is easy", "date": "2023-1-1" }, ... ]
deactivate server
```
sequenceDiagram
participant browser
participant server
browser->>server: POST https://studies.cs.helsinki.fi/exampleapp/new_note
activate server
server-->>data.jason: Save new note
browser->>server: GET https://studies.cs.helsinki.fi/exampleapp/notes
activate server
server-->>browser: HTML document
deactivate server
browser->>server: GET https://studies.cs.helsinki.fi/exampleapp/main.css
activate server
server-->>browser: the CSS file
deactivate server
browser->>server: GET https://studies.cs.helsinki.fi/exampleapp/main.js
activate server
server-->>browser: the JavaScript file
deactivate server
browser->>server: GET https://studies.cs.helsinki.fi/exampleapp/data.json
activate server
server-->>browser: [{ "content": "HTML is easy", "date": "2023-1-1" }, ... ]
deactivate server