Solve this todo section, problem is based on Data structure and algorithms.

package algs$42$;

public class MyDegrees $\{$

$//$ TODO: complete the methods

$//$ The constructor may take time proportional to V$+$E

$//$ The other methods should all take constant time

public MyDegrees$($Digraph G$)\{\}$

$//$ indegree of v

public int indegree$($int v$)\{$ return $0$; $\}$

$//$ outdegree of v

public int outdegree$($int v$)\{$ return $0$; $\}$

$//$ sources

public Iterable sources$()\{$ return null; $\}$

$//$ sinks

public Iterable sinks$()\{$ return null; $\}$

$//$ is G a map?

public boolean isMap$()\{$ return false; $\}$

$\}$