code: public void thaw(){
          attributes.put(getIdName(), null);
          compositeKeyPersisted = false;
          dirtyAttributeNames.addAll(attributes.keySet());
          frozen = false;
      }
docs: Unfreezes this model. After this method it is possible again to call save() and saveIt() methods.
  This method will erase the value of ID on this instance, while preserving all other attributes' values.
  
  If a record was deleted, it is frozen and cannot be saved. After it is thawed, it can be saved again, but it will
  generate a new insert statement and create a new record in the table with all the same attribute values.
  
  <p><p/>
  Synonym for {@link #defrost()}.