public int impact(MultiMappingStore m) {
   int impact = 0;
   for (ITree src : m.getSrcs()) {
     int pSize = src.getParents().size();
     if (pSize > impact) impact = pSize;
   }
   for (ITree src : m.getDsts()) {
     int pSize = src.getParents().size();
     if (pSize > impact) impact = pSize;
   }
   return impact;
 }
 public static String inSeed(ITree t) {
   return ITree.OPEN_SYMBOL + t.getLabel() + ITree.SEPARATE_SYMBOL + t.getType();
 }
 public static String outSeed(ITree t) {
   return t.getType() + ITree.SEPARATE_SYMBOL + t.getLabel() + ITree.CLOSE_SYMBOL;
 }
 public static int standardHash(ITree t) {
   return Integer.hashCode(t.getType()) + HashUtils.BASE * t.getLabel().hashCode();
 }