@type t() ::
%Envoy.Config.Filter.Network.HttpConnectionManager.V2.ScopedRoutes.ScopeKeyBuilder.FragmentBuilder.HeaderValueExtractor.KvElement{
__unknown_fields__: [
{field_number :: integer(), Protobuf.Wire.Types.wire_type(),
value :: term()}
],
key: String.t(),
separator: String.t()
}