code: def _load_schemes():
      """
      Extend default schemes with schemes from sysconfig.
      """
  
      sysconfig_schemes = _load_sysconfig_schemes() or {}
  
      return {
          scheme: {
              **INSTALL_SCHEMES.get(scheme, {}),
              **sysconfig_schemes.get(scheme, {}),
          }
          for scheme in set(
              itertools.chain(INSTALL_SCHEMES, sysconfig_schemes)
          )
      }
  
imports: import sys
  import os
  import contextlib
  import sysconfig
  import itertools
  from distutils._log import log
  from ..core import Command
  from ..debug import DEBUG
  from ..sysconfig import get_config_vars
  from ..file_util import write_file
  from ..util import convert_path, subst_vars, change_root
  from ..util import get_platform
  from ..errors import DistutilsOptionError, DistutilsPlatformError
  from .None import _framework_compat
  from ..None import _collections
  from site import USER_BASE
  from site import USER_SITE
label_desc: Use image node_id 2 for calling a global function with example usage: _load_schemes() and returns: unknown