code: private Glyph handlePEGroup(Set<PhysicalEntity> pes, String context) {
  		int sz = pes.size();		
  		if (sz > 1) {
  			List<Glyph> gs = getGlyphsOfPEs(pes, context);
  			return connectWithAND(gs);
  		} else if (sz == 1) {
  			PhysicalEntity pe = pes.iterator().next();
  			if(glyphMap.containsKey(convertID(pe.getUri())))
  				return getGlyphToLink(pe, context);
  		}
  		
  		//'pes' was empty
  		return null;
  	}
docs: /*
  Prepares the necessary construct for adding the given PhysicalEntity set to the Control
  being drawn.
  
  @param pes entities to use in control
  @return the glyph to connect to the appropriate place