Importing SpanData into opentelemetry-otlp?

[joshtriplett]

For the purposes of batch processing or testing, would it be possible to import a Vec<SpanData> into opentelemetry to be sent out via opentelemetry-otlp or the stdout pipeline? Concretely, I'd love to have a method that accepts a Vec<SpanData> and sends it through the same pipeline as those collected and fed in via tracing-opentelemetry.