RTC SCM: Copy Snapshot to other stream

I couldn't find this question in existing threads so let me ask.

Question:
I'm wondering how I can copy snapshot to other stream? I found the way changing owner of snapshot but no copy menu in eclipse client.

Reference Information:
As alternative way I accept baselines of all component in the stream, and re-create snapshot manually in other stream.

Back ground:
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Now there are three streams in my project,
  - A.dev stream      x number of dev teams  ( for development in each team )
  - B. merge stream x 1  ( to collect all the artifacts developed in each team )
  - C. Test stream    x 1 ( for testers to look at )

At stream B,  librarian collects all change sets, and make a snapshot when build error is zero.
And then librarian wants to copy snapshot from stream B to stream C to allow testers to use.

As you know, snapshot includes some component baselines.
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