This API is subject to change. Bug fixes and new features will be released based on developer feedback throughout the preview period.
Refines a filter to match items whose specified field has any value.
The isNotEmpty() method refines this filter to only match items where the
value of the specified field is not null or undefined.
If the field contains any value at all for a given item, including the empty string or an invalid value, that item will match the filter.
Field in which to check for a value.