Nullability of reference types in type of parameter 'value' of 'void MyEventMessageMapper.Context.set' doesn't match implicitly implemented member 'void IAmAMessageMapper<MyEvent>.Context.set' (possibly because of nullability attributes).

Nullability of reference types in type of parameter 'value' of 'void MyEventMessageMapperAsync.Context.set' doesn't match implicitly implemented member 'void IAmAMessageMapperAsync<MyEvent>.Context.set' (possibly because of nullability attributes).

Possible null reference argument for parameter 'topic' in 'MessageHeader.MessageHeader(string messageId, RoutingKey topic, MessageType messageType, Uri? source = null, string? type = null, DateTimeOffset? timeStamp = null, string? correlationId = null, RoutingKey? replyTo = null, string contentType = "text/plain", string partitionKey = "", Uri? dataSchema = null, string? subject = null, int handledCount = 0, TimeSpan? delayed = null)'.

Non-nullable property 'Header' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Body' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Nullability of reference types in value of type 'Task<MyEvent?>' doesn't match target type 'Task<MyEvent>'.

Non-nullable property 'Context' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Possible null reference argument for parameter 'topic' in 'MessageHeader.MessageHeader(string messageId, RoutingKey topic, MessageType messageType, Uri? source = null, string? type = null, DateTimeOffset? timeStamp = null, string? correlationId = null, RoutingKey? replyTo = null, string contentType = "text/plain", string partitionKey = "", Uri? dataSchema = null, string? subject = null, int handledCount = 0, TimeSpan? delayed = null)'.

Converting null literal or possible null value to non-nullable type.