code: protected ConversionDirectionType findDirectionInCatalysis(Conversion conv)
  	{
  		Set<ConversionDirectionType> dirs = new HashSet<ConversionDirectionType>();
  		for (Control control : conv.getControlledOf())
  		{
  			ConversionDirectionType dir = getCatalysisDirection(control);
  			if (dir != null) dirs.add(dir);
  		}
  		if (dirs.size() > 1) return ConversionDirectionType.REVERSIBLE;
  		else if (!dirs.isEmpty()) return dirs.iterator().next();
  		else return null;
  	}
docs: Searches the controlling catalysis for possible direction of the conversion.
  @param conv the conversion
  @return direction inferred from catalysis objects