func (n *node) size() int {
	sz, elsz := pageHeaderSize, n.pageElementSize()
	for i := 0; i < len(n.inodes); i++ {
		item := &n.inodes[i]
		sz += elsz + uintptr(len(item.key)) + uintptr(len(item.value))
	}
	return int(sz)
}
size returns the size of the node after serialization.
package bbolt
import (
	"bytes"
	"fmt"
	"reflect"
	"sort"
	"unsafe"
)
type node struct {
	bucket     *Bucket
	isLeaf     bool
	unbalanced bool
	spilled    bool
	key        []byte
	pgid       pgid
	parent     *node
	children   nodes
	inodes     inodes
}
func (n *node) root() *node {
	if n.parent == nil {
		return n
	}
	return n.parent.root()
}
func (n *node) minKeys() int {
	if n.isLeaf {
		return 1
	}
	return 2
}