SerializationException during PushEphemeral

[Mithgroth]

Greetings,
I'm getting a SerializationException while trying to use PushEphemeral.

Using the code in the test project,
v3.1.0

Type 'PushbulletSharp.Models.Requests.Ephemerals.NotificationEphemeral' with data contract name 'NotificationEphemeral:http://schemas.datacontract.org/2004/07/PushbulletSharp.Models.Requests.Ephemerals' is not expected. Consider using a DataContractResolver if you are using DataContractSerializer or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to the serializer.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Runtime.Serialization.SerializationException: Type 'PushbulletSharp.Models.Requests.Ephemerals.NotificationEphemeral' with data contract name 'NotificationEphemeral:http://schemas.datacontract.org/2004/07/PushbulletSharp.Models.Requests.Ephemerals' is not expected. Consider using a DataContractResolver if you are using DataContractSerializer or add any types not known statically to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding them to the list of known types passed to the serializer.