code: func Change(schema interface{}, changes ...map[string]interface{}) *Changeset {
  	ch := &Changeset{}
  	ch.changes = make(map[string]interface{})
  	ch.values, ch.types, _ = mapSchema(schema)
  
  	if len(changes) > 0 {
  		ch.changes = changes[0]
  	} else {
  		ch.changes = make(map[string]interface{})
  	}
  
  	return ch
  }
docs: // Change make a new changeset without changes and build from given schema. Returns new Changeset.