code: def _get_env(environment, name):
      # type: (Dict[str, str], str) -> str
      value = environment.get(
          name, _undefined
      )  # type: Union[str, Undefined]
  
      if isinstance(value, Undefined):
          raise UndefinedEnvironmentName(
              "{0!r} does not exist in evaluation environment.".format(
                  name
              )
          )
  
      return value
  
imports: from __future__ import absolute_import, division, print_function
  import operator
  import os
  import platform
  import sys
  from pyparsing import Forward, Group, Literal, ParseException, ParseResults, QuotedString, ZeroOrMore, stringEnd, stringStart
  from ._compat import string_types
  from ._typing import TYPE_CHECKING
  from .specifiers import InvalidSpecifier, Specifier
label_desc: Use image node_id 4 for calling a global function with example usage: _get_env(environment, name) and returns: value