name is the event kind.
public Optional<String> name()name is the event kind. Common values emitted by the LangChain/LangSmith tracer SDKs
include "start", "end", and "new_token", but applications may emit arbitrary
strings for their own instrumentation.
LangChainInvalidDataException: if the JSON field has an unexpected type (e.g. if
the server responded with an unexpected value).