code: public static boolean writeParticipants(Set<SIFInteraction> inters, OutputStream out)
  	{
  		if (!inters.isEmpty())
  		{
  			try
  			{
  				OutputStreamWriter writer = new OutputStreamWriter(out);
  				writeSourceAndTargetDetails(inters, writer);
  				writer.close();
  				return true;
  			}
  			catch (IOException e)
  			{
  				e.printStackTrace();
  			}
  		}
  		return false;
  	}
docs: Writes down the interaction participants' (nodes) details
  to the given output stream. Closes the stream at the end.
  
  @param inters binary interactions
  @param out stream to write
  @return true if any output produced successfully