[PENDING: update the comments] PathInterface.
public void addChild(PathInterface aChild)
public void addOperation(PathOperationInterface anOperation)
public PathInterface getChild(int aRank)
public PathOperationInterface getOperation(int aRank)
public int getRank()
public void insertChild(PathInterface aChild, int aRank)
public int numberOfChildren()
public int numberOfOperation()
public void setRank(int aValue)