--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/planemo/lib/python3.7/site-packages/pip/_internal/models/candidate.py	Fri Jul 31 00:32:28 2020 -0400
@@ -0,0 +1,36 @@
+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
+    from typing import Any
+
+
+class InstallationCandidate(KeyBasedCompareMixin):
+    """Represents a potential "candidate" for installation.
+    """
+
+    def __init__(self, project, version, link):
+        # type: (Any, str, Link) -> None
+        self.project = project
+        self.version = parse_version(version)  # type: _BaseVersion
+        self.link = link
+
+        super(InstallationCandidate, self).__init__(
+            key=(self.project, self.version, self.link),
+            defining_class=InstallationCandidate
+        )
+
+    def __repr__(self):
+        # type: () -> str
+        return "<InstallationCandidate({!r}, {!r}, {!r})>".format(
+            self.project, self.version, self.link,
+        )
+
+    def __str__(self):
+        return '{!r} candidate (version {} at {})'.format(
+            self.project, self.version, self.link,
+        )