Debug the code below $($ProductCollection$.$java$)$:

class ProductCollection$\{$

public Product$[]$ collection;

public int count;

int maximumSize;

public ProductCollection$()$

$\{$

maximumSize$=20$;

collection$=$new Product$[$maximumSize$]$;

count$=0$;

$\}$

public void addProduct$($int prodID,String prodName, double unitPrice,int prodQty$)$

$\{$

if$($count