code: public OutputStream createOutOutputStream(OutputStream os, String linkId) {
          return new InstrumentedOutputStream(collector(), Direction.Out, os, linkId);
      }
docs: This method returns an instrumented proxy output stream, to wrap
  the supplied output stream, which will record the written data. The
  optional link id can be used to initiate a link with the specified
  id (and disassociate the trace from the current thread).
  
  @param os The original output stream
  @param linkId The optional link id
  @return The instrumented output stream