@Override
    public String toString() {
        StringBuilder string = new StringBuilder();
        string.append("update of document '");
        string.append(docId);
        string.append("': ");
        string.append("create-if-non-existent=");
        string.append(getCreateIfNonExistent());
        string.append(": ");
        string.append("[");

        for (FieldUpdate fieldUpdate : id2FieldUpdates.values()) {
            string.append(fieldUpdate).append(" ");
        }
        string.append("]");

        if (fieldPathUpdates.size() > 0) {
            string.append(" [ ");
            for (FieldPathUpdate up : fieldPathUpdates) {
                string.append(up.toString()).append(" ");
            }
            string.append(" ]");
        }

        return string.toString();
    }
Returns the document type of this document update.

@return the document type of this document update
document/src/main/java/com/yahoo/document/DocumentUpdate.java