def load_installed_version(self):
        installed_packages = get_installed_pypackages()
        if self.package in installed_packages:
            self.version = "=={}".format(
                installed_packages[self.package].version)
def run(self):
    hdrs = self.distribution.headers
    if not hdrs:
      return

    self.mkpath(self.install_dir)
    for header in hdrs:
      (out, _) = self.mkdir_and_copy_file(header)
      self.outfiles.append(out)