TreeNode class:

$$ Represents a single node in the supermarket tree. Each node has a name $($such

as "Dairy" or "Milk"$),$ an array of children nodes $($children$),$ and the current size

of the children array $\{$size$).$

$$ Provides an overloaded constructor to initialize a node with a name and a

capacity for the number of children it can have.

$$ Provides a method addChild to add a child node to the current node