class_docstr: Abstract Parser class to be inherited by all StreamAlert Parsers
class_docstr_tok: ["Abstract","Parser","class","to","be","inherited","by","all","StreamAlert","Parsers"]
docstr: Return a default value for a given supported schema type
docstr_tok: ["Return","a","default","value","for","a","given","supported","schema","type"]
code: def default_optional_values(cls, key):
      """Return a default value for a given supported schema type"""
      # Return instances of types that are defined, or of the type being passed in
      return (
          cls._TYPE_MAP[key]() if isinstance(key, str) else type(key)()
      )
  
imports: from abc import ABCMeta, abstractmethod
  from copy import deepcopy
  import csv
  from fnmatch import fnmatch
  import json
  import logging
  import re
  import io
  import jmespath
  from streamalert.shared.logger import get_logger
label_desc: Use image node_id 16 for calling the ParserBase obj's underlying member method code with example usage: obj.default_optional_values(cls, key) and returns: unknown