Rust is failing when we have @required Timestamp

[ShubhamChaturvedi7]

Model:

// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0
namespace simple.types.timestamp

@aws.polymorph#localService(
  sdkId: "SimpleTimestamp",
  config: SimpleTimestampConfig,
)
service SimpleTypesTimestamp {
  version: "2021-11-01",
  resources: [],
  operations: [ GetTimestamp,  GetTimestampRequired],
  errors: [],
}

structure SimpleTimestampConfig {}

operation GetTimestamp {
  input: GetTimestampInput,
  output: GetTimestampOutput,
}

structure GetTimestampInput {
  value: Timestamp
}

structure GetTimestampOutput {
  value: Timestamp
}

operation GetTimestampRequired {
  input: GetTimestampRequiredInput,
  output: GetTimestampRequiredOutput,
}

structure GetTimestampRequiredInput {
  @required
  value: Timestamp
}

structure GetTimestampRequiredOutput {
  @required
  value: Timestamp
}

Output:

error[E0308]: mismatched types
  --> src/conversions/get_timestamp_required/_get_timestamp_required_input.rs:11:16
   |
11 |         value: crate::standard_library_conversions::otimestamp_to_dafny(&value.value),
   |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `Sequence<DafnyCharUTF16>`, found `Rc<Option<Sequence<DafnyCharUTF16>>>`