class_docstr: S3Payload tests
class_docstr_tok: ["S3Payload","tests"]
docstr: S3Payload - Read File
docstr_tok: ["S3Payload","-","Read","File"]
code: def test_read_file(self):
      """S3Payload - Read File"""
      value = "test_data".encode()
      boto3.resource("s3").Bucket(self._bucket).create()
      boto3.resource("s3").Bucket(self._bucket).put_object(
          Key=self._key, Body=value
      )
  
      payload = S3Payload(None, self._record)
      read_lines = list(payload._read_file())
      assert_equal(read_lines, [(1, value)])
  
imports: import json
  import gzip
  import os
  import tempfile
  import boto3
  from botocore.exceptions import ClientError
  from mock import patch
  from moto import mock_s3
  from nose.tools import assert_equal, assert_raises
  from pyfakefs import fake_filesystem_unittest
  from streamalert.classifier.payload.s3 import S3Payload, S3PayloadError
label_desc: Use image node_id 16 for calling the TestS3Payload obj's underlying member method code with example usage: obj.test_read_file() without return types