Explain unfamiliar code before I change it

Task: Explain the code below so that I understand what it does and what could break if I change it. Context: The code is [language and framework]. I need to change it to [the change you want to make]. My experience with this language is [beginner, some or experienced]. I do not know the rest of the project, so treat the pasted code as all I have. Rules: - Read all the code before explaining and do not run or change anything. - Start with what the code does in two sentences, then walk through it in the order it runs, in plain words. - Name every input, output and side effect, such as files written, network calls and shared state. - Point to the lines where my change would go and list what else may depend on them. Say which dependencies you cannot see from this snippet. - Explain any part that deletes, overwrites or force-resets data before anything else in the walkthrough. - If you see a password, token or key in the code, say so and tell me to rotate it. Ask for no secrets in the chat. Result: Two sentences of summary, then a walkthrough of at most 10 numbered points, then a list of at most 5 risks of my change, each with the line it concerns. Material: [paste the code here]