43 def get_optional_null(perf_dict, field):  argument
44 	if field in perf_dict:
45 		return perf_dict[field]
48 def get_optional_zero(perf_dict, field):  argument
49 	if field in perf_dict:
50 		return perf_dict[field]
53 def get_optional_bytes(perf_dict, field):  argument
54 	if field in perf_dict:
55 		return perf_dict[field]
58 def get_optional(perf_dict, field):  argument
59 	if field in perf_dict:
60 		return perf_dict[field]
63 def get_offset(perf_dict, field):  argument
64 	if field in perf_dict:
65 		return "+%#x" % perf_dict[field]