The Tree-o-Matic Software company specializes in all things related to trees. You have been asked to design a new utility class to verify whether a given tree-based array is a Binary Search Tree.

Assignment:

Create a BSTChecker class with the following capabilities:

Feature	Signature	Requirement
Constructors	N/A	A utility classno constructor needed
Methods	static boolean isValid(Integer [] intArray)	Returns true if array is a valid binary search tree. Preconditions: throws NullPointerException if intArray is null. Note: must be explicitly thrown. Implementation does not need to be recursive.