class_docstr: Test class for ParserBase classmethods
class_docstr_tok: ["Test","class","for","ParserBase","classmethods"]
docstr: ParserBase - Apply Envelope
docstr_tok: ["ParserBase","-","Apply","Envelope"]
code: def test_apply_envelope(self):
      """ParserBase - Apply Envelope"""
      record = {"key": "value"}
      envelope = {"env_key_01": "value"}
  
      ParserBase._apply_envelope(record, envelope)
  
      expected_record = {
          "key": "value",
          "streamalert:envelope_keys": {"env_key_01": "value"},
      }
  
      assert_equal(record, expected_record)
  
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 7 for calling the TestParserBaseClassMethods obj's underlying member method code with example usage: obj.test_apply_envelope() without return types