CreateClusterConstrainedNull

## from http://xsisupport.com/2012/03/17/python-example-constraining-nulls-to-components/  + missingkey Select new nulls.
from win32com.client import constants as C
si = Application
log = si.LogMessage
selList = []


if si.Selection.Count > 0 and si.ClassName(si.Selection(0)) == 'CollectionItem' and si.Selection(0).SubComponent is not None:

    # pnt, poly, edge, ...
    clusterType = si.Selection(0).Type.replace( 'SubComponent','' )
    o = si.Selection(0).SubComponent.Parent3DObject

    for i in si.Selection(0).SubElements:
        c = o.ActivePrimitive.Geometry.AddCluster( clusterType, "", [i] )
        n = si.ActiveSceneRoot.AddNull()
        n.Kinematics.AddConstraint( "ObjectToCluster", c )
        selList.append( n )

si.SelectObj( selList )