code: def extract_subsec(self):
          '''
          Extract microseconds
          '''
          fields = [
              'Image SubSecTimeOriginal',
              'EXIF SubSecTimeOriginal',
              'Image SubSecTimeDigitized',
              'EXIF SubSecTimeDigitized',
              'Image SubSecTime',
              'EXIF SubSecTime'
          ]
          sub_sec, _ = self._extract_alternative_fields(
              fields, default='', field_type=str)
          return sub_sef extract_subsec(self):
          '''
          Extract microseconds
          '''
          fields = [
              'Image SubSecTimeOriginal',
              'EXIF SubSecTimeOriginal',
              'Image SubSecTimeDigitized',
              'EXIF SubSecTimeDigitized',
              'Image SubSecTime',
              'EXIF SubSecTime'
          ]
          sub_sec, _ = self._extract_alternative_fields(
              fields, default='', field_type=str)
          return sub_sec
docs: Extract microseconds