public Optional<String> capacity() {
        return Optional.ofNullable(this.capacity);
    }
@return Capacity is the value reported by the CSI driver in its GetCapacityResponse for a GetCapacityRequest with topology and parameters that match the previous fields.

The semantic is currently (CSI spec 1.2) defined as: The available capacity, in bytes, of the storage that can be used to provision volumes. If not set, that information is currently unavailable.
sdk/java/src/main/java/com/pulumi/kubernetes/storage/v1beta1/outputs/CSIStorageCapacity.java