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: document.go
    path of file: ./repos/podman/vendor/go.mongodb.org/mongo-driver/x/bsonx/bsoncore
    
    the code of the file until where you have to start completion: // Copyright (C) MongoDB, Inc. 2017-present.
//
// License
    
func (d Document) DebugString() string {
	if len(d) < 5 {
		return "<malformed>"
	}
	var buf strings.Builder
	buf.WriteString("Document")
	length, rem, _ := ReadLength(d) // We know we have enough bytes to read the length
	buf.WriteByte('(')
	buf.WriteString(strconv.Itoa(int(length)))
	length -= 4
	buf.WriteString("){")
	var elem Element
	var ok bool
	for length > 1 {
		elem, rem, ok = ReadElement(rem)
		length -= int32(len(elem))
		if !ok {
			buf.WriteString(fmt.Sprintf("<malformed (%d)>", length))
			break
		}
		buf.WriteString(elem.DebugString())
	}
	buf.WriteByte('}')

	return buf.String()
}