rem: NodeChecker(bplustree_node *node, int32 nodeSize, const char *text)
add: NodeChecker(const bplustree_node *node, int32 nodeSize, const char *text)
context: 		NodeChecker(bplustree_node *node, int32 nodeSize, const char *text)			:			fNode(node),			fSize(nodeSize),			fText(text)		{			Check("integrity check failed on construction.");		}