Get all available regions for the EC2 service.

        :type region_names: list of str
        :param region_names: Names of regions to limit output

        :type filters: dict
        :param filters: Optional filters that can be used to limit
                        the results returned.  Filters are provided
                        in the form of a dictionary consisting of
                        filter names as the key and filter values
                        as the value.  The set of allowable filter
                        names/values is dependent on the request
                        being performed.  Check the EC2 API guide
                        for details.

        :rtype: list
        :return: A list of :class:`boto.ec2.regioninfo.RegionInfo`

def get_all_regions(self, region_names=None, filters=None):
        """
        Get all available regions for the EC2 service.

        :type region_names: list of str
        :param region_names: Names of regions to limit output

        :type filters: dict
        :param filters: Optional filters that can be used to limit
                        the results returned.  Filters are provided
                        in the form of a dictionary consisting of
                        filter names as the key and filter values
                        as the value.  The set of allowable filter
                        names/values is dependent on the request
                        being performed.  Check the EC2 API guide
                        for details.

        :rtype: list
        :return: A list of :class:`boto.ec2.regioninfo.RegionInfo`
        """
        params = {}
        if region_names:
            self.build_list_params(params, region_names, 'RegionName')
        if filters:
            self.build_filter_params(params, filters)
        regions =  self.get_list('DescribeRegions', params,
                                 [('item', RegionInfo)], verb='POST')
        for region in regions:
            region.connection_cls = EC2Connection
        return regions