so we have: 
```
component: tripleo
(...)
tags:
  antelope:
    component: common
  bobcat:
    component: common
  bobcat-uc:
    component: common
  rocky: null
  stein: null
  train: null
  ussuri: null
  victoria: null
  wallaby: null
  xena: null
  yoga: null
  zed: null
```
so why leaving component:tripleo in main key? we have now  different answers, depending on way of asking