class_docstr: Test class for ParserBase
class_docstr_tok: ["Test","class","for","ParserBase"]
docstr: ParserBase - Extract Envelope, None
docstr_tok: ["ParserBase","-","Extract","Envelope",",","None"]
code: def test_extract_envelope_none(self):
      """ParserBase - Extract Envelope, None"""
      record = {"key": "value"}
  
      parser = ParserBase(None)
      envelope = parser._extract_envelope(record)
      assert_equal(envelope, None)
  
imports: import json
  from mock import patch
  from nose.tools import assert_equal
  import streamalert.classifier.parsers
  from streamalert.classifier.parsers import ParserBase
label_desc: Use image node_id 12 for calling the TestParserBaseMethods obj's underlying member method code with example usage: obj.test_extract_envelope_none() without return types