// Set the left underlying node
 public void SetLeft(BinaryNode <T> left) => this.left = left;
 // Set the right underlying node
 public void SetRight(BinaryNode <T> right) => this.right = right;
 // Constructor
 public BinaryNode(T data, BinaryNode <T> left, BinaryNode <T> right)
 {
     this.data  = data;
     this.left  = left;
     this.right = right;
 }