def remove(self, elem):
        """Remove a requirement.

        :param elem: a string or :class:`Requirement` instance.
        """
        if isinstance(elem, text_type):
            for requirement in self:
                if requirement.package == elem:
                    return super(Requirements, self).remove(requirement)
        return super(Requirements, self).remove(elem)
def downloadNewsPage(self, strTagName=None):
        if strTagName is None:
            #未指定 tag
            lstStrObtainedTagName = self.db.fetchallCompletedObtainedTagName()
            for strObtainedTagName in lstStrObtainedTagName:
                self.downloadNewsPageWithGivenTagName(strTagName=strObtainedTagName)
        else:
            #有指定 tag 名稱
            self.downloadNewsPageWithGivenTagName(strTagName=strTagName)