code: def normalize_instrument(instrument):
      return instrument.upper()
  
imports: from pyalgotrade.barfeed import dbfeed
  from pyalgotrade.barfeed import membf
  from pyalgotrade import bar
  from pyalgotrade.utils import dt
  import sqlite3
  import os
label_desc: Use image node_id 1 for calling a global function with example usage: normalize_instrument(instrument) and returns: instrument