code: def create_connection(port=_PORT_, timeout=_TIMEOUT_, restart=False):
      
      if _CON_SYM_ in globals():
          if not isinstance(globals()[_CON_SYM_], pdblp.BCon):
              del globals()[_CON_SYM_]
  
      if (_CON_SYM_ in globals()) and (not restart):
          con = globals()[_CON_SYM_]
          if getattr(con, '_session').start(): con.start()
          return con, False
  
      else:
          con = pdblp.BCon(port=port, timeout=timeout)
          globals()[_CON_SYM_] = con
          con.start()
          return con, True
docs: Create Bloomberg connection
  
      Returns:
          (Bloomberg connection, if connection is new)