@type t() :: %UmaDb.V1.ReadRequest{
  __unknown_fields__: [Protobuf.unknown_field()],
  backwards: boolean() | nil,
  batch_size: non_neg_integer() | nil,
  limit: non_neg_integer() | nil,
  query: UmaDb.V1.Query.t() | nil,
  start: non_neg_integer() | nil,
  subscribe: boolean() | nil
}