code: def p_operator_range_before_datetime(p):
      "operator_range : BEFORE datetime"
      end = p[2]
      p[0] = lambda ref: (None, end(ref))
  
imports: from datetime import datetime, date, time, timedelta
  from guild import _yacc
  from .None import trlex
label_desc: Use image node_id 39 for calling a global function with example usage: p_operator_range_before_datetime(p) without return types