Function set_instance_metadata 

pub fn set_instance_metadata<T: Config>(
    instance: InstanceId,
    key: MetadataKeyOf<T>,
    value: Option<MetadataValueOf<T>>,
)

Set or remove an instance-specific metadata override.

Only the collection owner may mutate metadata. None releases an existing entry’s deposit; when the key is absent it is a successful no-op.

Warning: Doc-Only

This function is an automatically generated, and is doc-only, uncallable stub. See the real version in Pallet::set_instance_metadata.