NewMaxHeap initializes a heap with a closerToRootFunction that simply returns true if the first arg is larger than the second.

NewMinHeap initializes a heap with a closerToRootFunction that simply returns true if the first arg is smaller than the second.

MaxHeap is an implementation of max heap.

MinHeap is an implementation of a min heap.

HeapNode is an interface making the type for a Min/MaxHeap node flexible nodes must be be able to state their value to be sorted by.