capybara/virtualenv/lib/python2.7/site-packages/pip/req/req_install.py
def populate_link(self, finder, upgrade):
        """Ensure that if a link can be found for this, that it is found.

        Note that self.link may still be None - if Upgrade is False and the
        requirement is already installed.
        """
        if self.link is None:
            self.link = finder.find_requirement(self, upgrade)
def populate_link(self, finder, upgrade):
        """Ensure that if a link can be found for this, that it is found.

        Note that self.link may still be None - if Upgrade is False and the
        requirement is already installed.
        """
        if self.link is None:
            self.link = finder.find_requirement(self, upgrade)
Ensure that if a link can be found for this, that it is found.

        Note that self.link may still be None - if Upgrade is False and the
        requirement is already installed.