BigRoy

"""
  maya.cmds.listHistory() will always include the node itself when history is returned.
  Here we're testing whether it's always the first node returned, if not a RuntimeError is raised.
  
  We're also checking whether all nodes in the scene will return a valid history list, which isn't True.
  The 'defaultColorMgtGlobals' node returns None instead of an empty list.
"""

from maya import cmds