You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: cursor.go
    path of file: ./repos/dep/vendor/github.com/boltdb/bolt
    
    the code of the file until where you have to start completion: package bolt

import (
	"bytes"
	"fmt"
	"sort"
)

// Cursor represents an iterator that can traverse over all key/value pairs in a bucket in sorted order.
// Cursors see nested buckets with value == nil.
// Cursors can be obtained from a transaction and are valid a
    
func (c *Cursor) Seek(seek []byte) (key []byte, value []byte) {
	k, v, flags := c.seek(seek)

	// If we ended up after the last element of a page then move to the next one.
	if ref := &c.stack[len(c.stack)-1]; ref.index >= ref.count() {
		k, v, flags = c.next()
	}

	if k == nil {
		return nil, nil
	} else if (flags & uint32(bucketLeafFlag)) != 0 {
		return k, nil
	}
	return k, v
}