i need help creating the classes for graphhelptools

public class Graphhelptools$\{$

$//$ return an array containing the vertex numbers of an optimal VC$.$

$$ public static int$[]$ exactVC$($Graph inputGraph$)\{$

$$ return null;

$\}$

$$

$//$ return $($in polynomial time$)$ an array containing the vertex numbers of a VC$.$

$$ public static int$[]$ inexactVC$($Graph inputGraph$)\{$

$$ return null;

$\}$

$$

$//$ return an array containing the vertex numbers of an optimal IS$.$

$$ public static int$[]$ optimalIS$($Graph inputGraph$)\{$

$$ return null;

$\}$

$$

$//$ return $($in polynomial time$)$ an array containing the vertex numbers of a IS$.$

$$ public static int$[]$ inexactIS$($Graph inputGraph$)\{$

$$ return null;

$\}$

$\}$

public class Graph $\{$

$$ private int$[][]$ graph; $//$ Must be of the form $[$vertex$][$vertexNeighbor$1,$ vertexNeighbor$2,...]$

$$ public Graph$($String fileName$)\{$

$$ try $($BufferedReader br $=$ new BufferedReader$($new FileReader$($fileName$)))\{$

$$ String line $=$ br$.$readLine$()$;

$$ if $($line$.$startsWith$("$numVert$"))\{$

$$ graph $=$ new int$[$Integer$.$parseInt$($line$.$substring$($line$.$indexOf$("")+1))][]$;

$$ line $=$ br$.$readLine$()$;

$$ line $=$ br$.$readLine$()$;

$$ while $($line $!=$ null$)\{$

$$ String$[]$ values $=$ line.split$("")$;

$$ int vertexNum $=$ Integer.parseInt$($values$[0])$;

$$ int numNeighbors $=$ Integer.parseInt$($values$[1])$;

$$ graph$[$vertexNum$]=$ new int$[$numNeighbors$]$;

$$ for $($int i $=0$; i $<$ numNeighbors; i$++)\{$

$$ graph$[$vertexNum$][$i$]=$ Integer.parseInt$($values$[2+$ i$])$;

$\}$

$$ line $=$ br$.$readLine$()$;

$\}$

$\}$

$\}$ catch $($FileNotFoundException ex$)\{$

$$ System.out.println$("$File not found. Try putting file in same filder as src folder."$)$;

$\}$ catch $($IOException ex$)\{$

$$ System.out.println$("$Exception: $"+$ ex$.$toString$())$;

$\}$

$\}$

$$ public int$[][]$ getGraph$()\{$

$$ return graph;

$\}$

$\}$