what does this code do?


    @patch.dict(
        "os.environ",
        {"AZURE_OCR_ENDPOINT": "AZURE_OCR_ENDPOINT/", "AZURE_OCR_KEY": "AZURE_OCR_KEY"},
    )
    @override_settings(
        AZURE_OCR_ENDPOINT="AZURE_OCR_ENDPOINT/", AZURE_OCR_KEY="AZURE_OCR_KEY"
    )
    @patch.dict("sys.modules", {__package__ + ".minio_connector": MagicMock()})
    @patch.dict("sys.modules", {"time": MagicMock()})
    @patch.dict("sys.modules", spacy=MagicMock())
    @patch(__package__ + ".paid_ocr.requests", autospec=True)
    def test_paid_ocr(self, requests_mock):
        from .minio_connector import MinIOConnector as minio_mock
        from .paid_ocr import AzureOCRFromS3

        expected_pages = ["page1", "page2", "page3"]
        minio_mock.return_value.read_from_s3.return_value = self.get_pdf(
            expected_pages, True
        )

        ocr = AzureOCRFromS3("s3://test")

        expected_headers = {
            "Content-Type": "application/pdf",
            "Ocp-Apim-Subscription-Key": "AZURE_OCR_KEY",
        }
        expected_url = "AZURE_OCR_ENDPOINT/formrecognizer/documentModels/prebuilt-document:analyze?api-version=2023-07-31&pages=1-3"

        requests_mock.post.return_value = MockResponse(
            status_code=202, headers={"operation-location": "operation-location-url"}
        )
        requests_mock.get.return_value = MockResponse(
            status_code=200,
            data={
                "status": "succeeded",
                "analyzeResult": {
                    "content": "\n".join(expected_pages),
                    "pages": [
                        {"lines": [{"content": expected_pages[0]}]},
                        {"lines": [{"content": expected_pages[1]}]},
                        {"lines": [{"content": expected_pages[2]}]},
                    ],
                },
            },
        )
        pages = ocr.extract_text(max_ocr_pages=3, return_as_list=True)

        requests_mock.post.assert_called_once_with(
            url=expected_url,
            data=minio_mock.return_value.read_from_s3.return_value,
            headers=expected_headers,
            verify=False,
        )

        expected_url = "operation-location-url"
        expected_headers = {"Ocp-Apim-Subscription-Key": "AZURE_OCR_KEY"}
        requests_mock.get.assert_called_once_with(
            url=expected_url, headers=expected_headers, verify=False
        )

        self.assertEqual(["page1\n", "page2\n", "page3\n"], pages)
        requests_mock.reset_mock()

        expected_headers = {
            "Content-Type": "application/pdf",
            "Ocp-Apim-Subscription-Key": "AZURE_OCR_KEY",
        }
        expected_url = "AZURE_OCR_ENDPOINT/formrecognizer/documentModels/prebuilt-document:analyze?api-version=2023-07-31&pages=1-3"

        pages = ocr.extract_text(max_ocr_pages=3, max_llm_pages=2, return_as_list=True)

        requests_mock.post.assert_called_once_with(
            url=expected_url,
            data=minio_mock.return_value.read_from_s3.return_value,
            headers=expected_headers,
            verify=False,
        )

        expected_url = "operation-location-url"
        expected_headers = {"Ocp-Apim-Subscription-Key": "AZURE_OCR_KEY"}
        requests_mock.get.assert_called_once_with(
            url=expected_url, headers=expected_headers, verify=False
        )

        self.assertEqual(["page1\n", "page2\n"], pages)