code: def get(self, requirement):
          
          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))
docs: 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.