code: protected Set<Interaction> getDownstreamInteractions(Collection<Interaction> inters)
  	{
  		Set<Interaction> set = new HashSet<Interaction>();
  
  		for (Interaction inter : inters)
  		{
  			if (inter instanceof Conversion)
  			{
  				Conversion conv = (Conversion) inter;
  				ConversionDirectionType dir = conv.getConversionDirection();
  
  				if (dir == ConversionDirectionType.REVERSIBLE ||
  					(dir == ConversionDirectionType.RIGHT_TO_LEFT && conv.getRight().contains(pe)) ||
  					((dir == ConversionDirectionType.LEFT_TO_RIGHT || dir == null) &&
  						conv.getLeft().contains(pe)))
  				{
  					set.add(conv);
  				}
  			}
  			else if (inter instanceof Control)
  			{
  				set.add(inter);
  			}
  		}
  		return set;
  	}
docs: Gets the downstream interactions among the given set.
  @param inters Interactions to search
  @return Downstream interactions