PREVIEW: This is a preview API. Preview APIs are production quality, but can be changed on a major version without a deprecation path.
Number of attributes that can be sorted at the same time. Possible values are:
- "none": no sorting is supported.
- "single": only one attribute can be sorted at a time.
- "multiple": more than one attribute can be sorted at a time.
The interface for oj.SortCapability