code: def truncate(var):
      var = str(var)
      if len(var) > 500:
          var = "%s..." % var[:500]
      return var
  
imports: import sys
  import os
  from metaflow.exception import MetaflowException
  from metaflow import current
  from metaflow.cards import get_cards
  from metaflow.plugins.cards.exception import CardNotPresentException
label_desc: Use image node_id 3 for calling a global function with example usage: truncate(var) and returns: var