How to find if a customer is logged in or not in Magento 2.
If the customer is logged in then how to get customer data from a session?
To check if a customer is logged in or not in Magento 2, you can use the following methods:

1. Using the `$this->customerSession->isLoggedIn()` method in a custom Magento 2 block, controller or observer:
```php
namespace Vendor\Module\Block;

use Magento\Customer\Model\Session;

class MyBlock
{
    protected $customerSession;

    public function __construct(
        Session $customerSession
    ) {
        $this->customerSession = $customerSession;
I want to write a software design document for a new product `Chateval`, which can make it easier to evaluate generative AI systems (e.g., chatgpt and claude). Chateval can (1) provide many evaluation scenarios, from text writing to code and math, and (2) support many evaluation metrics, e.g. helpfulness, relevance and factuality. It not only provides developers with optimization directions, but also helps users use generative ai products such as chatgpt more reliably. Please help me finish the document that follows the structure:  [Overview],  [Goals], [Use Cases], [API Design], [Milestones], [Open Questions], [People].

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# Chateval: A Framework for Evaluating and Optimizing Generative AI Systems

## Overview

Chateval is a software framework designed to evaluate and optimize the performance of generative AI models, such asChatGPT and Claude, across a wide range of scenarios and evaluation metrics. Chateval aims to provide developers with actionable insights for model improvement and to help users use generative AI more reliably and confidently.

## Goals

* Enable comprehensive evaluation of generative AI system performance, encompassing a variety of scenarios and metrics.