Find packages matching ``requirement``.

        :param requirement: Requirement to match against repository packages.
        :type requirement: `str` or :class:`.Requirement`
        :returns: :func:`list` of matching :class:`.Package` objects.

def get(self, requirement):
        """Find packages matching ``requirement``.

        :param requirement: Requirement to match against repository packages.
        :type requirement: `str` or :class:`.Requirement`
        :returns: :func:`list` of matching :class:`.Package` objects.

        """
        if isinstance(requirement, basestring):
            requirement = Requirement.parse(requirement)
        return sorted(p for p in self.packages
                      if requirement.name == p.name and requirement.match(p))