question: public String toString ( ) { StringBuilder buf = new StringBuilder ( ) ; for ( Node node1 : nodesToVariables . keySet ( ) ) { buf . append ( "\n" ) ; buf . append ( ( node1 ) ) ; buf . append ( ": " ) ; DiscreteVariable variable = nodesToVariables . get ( ( node1 ) ) ; for ( int j = 0 ; j < variable . getNumCategories ( ) ; j ++ ) { buf . append ( variable . getCategory ( j ) ) ; if ( j < variable . getNumCategories ( ) - 1 ) { buf . append ( ", " ) ; } } } return buf . toString ( ) ; }
target:  Prints out the list of values for each node.