boskos/client/client.go
func (c *Client) Metric(rtype string) (common.Metric, error) {
	return c.metric(rtype)
}
func (c *Client) Metric(rtype string) (common.Metric, error) {
	return c.metric(rtype)
}
// Metric will query current metric for target resource type.
// Return a common.Metric object on success.