code: public StreamPlan transferFiles(InetAddress to, Collection<StreamSession.SSTableStreamingSections> sstableDetails)
      {
          coordinator.transferFiles(to, sstableDetails);
          return this;
  
      }
docs: Add transfer task to send given SSTable files.
  
  @param to endpoint address of receiver
  @param sstableDetails sstables with file positions and estimated key count.
  this collection will be modified to remove those files that are successfully handed off
  @return this object for chaining