text: import argparse
  import json
  #import logging
  
  from vntree import Node
  
  #logger = logging.getLogger(__name__)
  #logger.setLevel(logging.DEBUG)
  #ch = logging.StreamHandler()
  #logger.addHandler(ch)
  
  description = """A simple tree data structure based on vntree.Node class."""
  
  
  aparser = argparse.ArgumentParser(description=description)
  aparser.add_argument("case", help="Specify an example case to run.", 
      nargs='?', default="basic",
      choices=["basic", "world"])
  args = aparser.parse_args()
  
  
  
  
  if args.case == "basic":
      rootnode   = Node('ROOT')
      Node("1st child", parent=rootnode)
      child2 = Node("2nd child", rootnode)
      Node("grand-child1", child2)
      Node("grand-child2", child2)
      child3 = Node("3rd child", rootnode)
      Node("another child", rootnode)
      grandchild3 = Node(parent=child3, name="grand-child3")
      ggrandchild = Node("great-grandchild", grandchild3)
      Node("great-great-grandchild", ggrandchild)
      Node(None, grandchild3, {"_vntree":{"name":"name-in-data"}})
  
  
  if args.case == "world":
      rootnode = Node('The World', data={"population":7762609412}) 
      europe = Node('Europe', rootnode)
      Node('Belgium', europe, {"capital":"Brussels","population":11515793})
      europe.add_child( Node('Greece', data={"capital":"Athens","population":10768477}) )
      scandinavia = Node('Scandinavia', europe)
      europe.add_child( Node('Spain', data={"capital":"Madrid","population":46733038}) )
      denmark = Node('Denmark', scandinavia, {"capital":"Copenhagen","population":5822763})
      scandinavia.add_child( Node('Sweden', data={"capital":"Stockholm","population":10302984}) )
      Node('Norway', scandinavia, {"capital":"Oslo","population":5421241})
      Node('Faroe Islands', denmark)
      denmark.add_child( Node("Greenland") )
      samerica = Node('South America', rootnode)
      Node('Chile', samerica, {"capital":"Santiago","population":17574003})
  
                      
  
  print("\n", rootnode.to_texttree())
  