code: function _prop2CptDepsMapping (propname, dep) {
          // if ($indexOf(_computedKeys, dep))
          //    return $warn('Dependency should not computed property')
          $util.patch(_cptDepsMapping, dep, [])
  
          var dest = _cptDepsMapping[dep]
          if ($indexOf(dest, propname)) return
          dest.push(propname)
      }
docs: Add dependence to "_cptDepsMapping"
  @param propname <String> property name
  @param dep <String> dependency name