code: def make_break(lineno, p):
      
      global last_brk_linenum
  
      if not OPTIONS.enableBreak.value or lineno == last_brk_linenum or is_null(p):
          return None
  
      last_brk_linenum = lineno
      return make_sentence('CHKBREAK', make_number(lineno, lineno, TYPE.uinteger))
docs: Checks if --enable-break is set, and if so, calls
      BREAK keyboard interruption for this line if it has not been already
      checked