mocktracer/mocktracer.go
func (t *MockTracer) RegisterExtractor(format interface{}, extractor Extractor) {
	t.extractors[format] = extractor
}
func (t *MockTracer) RegisterExtractor(format interface{}, extractor Extractor) {
	t.extractors[format] = extractor
}
func ( t * MockTracer ) RegisterExtractor ( format interface { } , extractor Extractor ) { t . extractors [ format ] = extractor }
// RegisterExtractor registers extractor for given format
RegisterExtractor registers extractor for given format