code: protected Set<PhysicalEntity> getConvParticipants(Conversion conv, RelType type)
  	{
  		ConversionDirectionType dir = getDirection(conv);
  
  		if (dir == ConversionDirectionType.REVERSIBLE)
  		{
  			HashSet<PhysicalEntity> set = new HashSet<PhysicalEntity>(conv.getLeft());
  			set.addAll(conv.getRight());
  			return set;
  		}
  		else if (dir == ConversionDirectionType.RIGHT_TO_LEFT)
  		{
  			return type == RelType.INPUT ? conv.getRight() : conv.getLeft();
  		}
  		else return type == RelType.OUTPUT ? conv.getRight() : conv.getLeft();
  	}
docs: Gets input ot output participants of the Conversion.
  @param conv Conversion to get participants
  @param type input or output
  @return related participants