docstr: Returns whether ``pkg-config`` is available on the current system
  and it knows about igraph or not.
docstr_tok: ["Returns","whether","``","pkg-config","``","is","available","on","the","current","system","and","it","knows","about","igraph","or","not","."]
code: def has_pkgconfig(self) -> bool:
      """Returns whether ``pkg-config`` is available on the current system
      and it knows about igraph or not."""
      if self._has_pkgconfig is None:
          if self.use_pkgconfig:
              _, exit_code = get_output_single_line(
                  ["pkg-config", "igraph"]
              )
              self._has_pkgconfig = exit_code == 0
          else:
              self._has_pkgconfig = False
      return self._has_pkgconfig
  
imports: import os
  import platform
  import sys
  from setuptools import find_packages, setup, Command, Extension
  import glob
  import shlex
  import shutil
  import subprocess
  import sysconfig
  from contextlib import contextmanager
  from pathlib import Path
  from select import select
  from shutil import which
  from time import sleep
  from typing import List, Iterable, Iterator, Optional, Tuple, TypeVar, Union
label_desc: Use image node_id 2 for calling the BuildConfiguration obj's underlying member method code with example usage: obj.has_pkgconfig() and returns: self