question: private int indexOfElementInLevel ( int element , int level [ ] ) throws Exception { for ( int i = 0 ; i < level . length ; i ++ ) { if ( level [ i ] == element ) { return i ; } } throw new Exception ( "Error. Didn't find element " + m_nodes . get ( element ) . ID + " in level. Inspect code for " + "weka.gui.graphvisualizer.HierarchicalBCEngine" ) ; }
target:  Returns the index of an element in a level. Must never be called with the wrong element and the wrong level, will throw an exception otherwise. It takes as agrument the index of the element (in the m_nodes vector) and the level it is supposed to be in (as each level contains the indices of the nodes present in that level).