text: from pip._vendor.packaging.version import parse as parse_version
  
  from pip._internal.utils.models import KeyBasedCompareMixin
  from pip._internal.utils.typing import MYPY_CHECK_RUNNING
  
  if MYPY_CHECK_RUNNING:
      from pip._vendor.packaging.version import _BaseVersion
      from pip._internal.models.link import Link
  
  
  class InstallationCandidate(KeyBasedCompareMixin):
      """Represents a potential "candidate" for installation.
      """
  
      def __init__(self, name, version, link):
          # type: (str, str, Link) -> None
          self.name = name
          self.version = parse_version(version)  # type: _BaseVersion
          self.link = link
  
          super(InstallationCandidate, self).__init__(
              key=(self.name, self.version, self.link),
              defining_class=InstallationCandidate
          )
  
      def __repr__(self):
          # type: () -> str
          return "<InstallationCandidate({!r}, {!r}, {!r})>".format(
              self.name, self.version, self.link,
          )
  
      def __str__(self):
          # type: () -> str
          return '{!r} candidate (version {} at {})'.format(
              self.name, self.version, self.link,
          )
  