Json decoding exception on assistant run steps

[voqaldev]

Description

When deserializing RunStep (specifically RunStepDetails), the following error occurs:

Caused by: kotlinx.serialization.json.internal.JsonDecodingException: Polymorphic serializer was not found for class discriminator 'message_creation'
JSON input: .....ge_creation":{"message_id":"msg_dvN6jgl0m7aby9JKJkcEulTg"}}}
	at kotlinx.serialization.json.internal.JsonExceptionsKt.JsonDecodingException(JsonExceptions.kt:24)
	at kotlinx.serialization.json.internal.JsonExceptionsKt.JsonDecodingException(JsonExceptions.kt:32)
	at kotlinx.serialization.json.internal.PolymorphicKt.throwSerializerNotFound(Polymorphic.kt:79)
	at kotlinx.serialization.json.internal.PolymorphicKt.decodeSerializableValuePolymorphic(Polymorphic.kt:68)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:81)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableValue(AbstractDecoder.kt:43)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableElement(AbstractDecoder.kt:70)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableElement(StreamingJsonDecoder.kt:165)
	at kotlinx.serialization.encoding.CompositeDecoder$DefaultImpls.decodeSerializableElement$default(Decoding.kt:533)
	at kotlinx.serialization.internal.CollectionLikeSerializer.readElement(CollectionSerializers.kt:80)
	at kotlinx.serialization.internal.AbstractCollectionSerializer.readElement$default(CollectionSerializers.kt:51)
	at kotlinx.serialization.internal.AbstractCollectionSerializer.merge(CollectionSerializers.kt:36)
	at kotlinx.serialization.internal.AbstractCollectionSerializer.deserialize(CollectionSerializers.kt:43)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:70)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableValue(AbstractDecoder.kt:43)
	at kotlinx.serialization.encoding.AbstractDecoder.decodeSerializableElement(AbstractDecoder.kt:70)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableElement(StreamingJsonDecoder.kt:165)
	at com.aallam.openai.api.core.PaginatedList$$serializer.deserialize(PaginatedList.kt:6)

Steps to Reproduce

1. Create an Assistant run
2. Try to get the run steps

Environment

• openai-kotlin version: 3.6.0
• Kotlin version: 1.8.0
• OS: Ubuntu 22