@type t() :: %LabelingIR.Assignment{
  existing_labels: [LabelingIR.Label.t()],
  expires_at: DateTime.t() | nil,
  id: String.t(),
  lineage_ref: LabelingIR.Types.lineage_ref() | nil,
  metadata: map(),
  namespace: String.t() | nil,
  queue_id: String.t(),
  sample: LabelingIR.Sample.t(),
  schema: LabelingIR.Schema.t(),
  tenant_id: String.t()
}