add_new_node_attribute
Description:
Requests that for any new node managed (eg.
created) by this, a new attribute will be set. This allows one to customize the attributes of new nodes created by an existing TreeManager.
As a side effect, if value is null, then the corresponding attribute, if it was set, is unset.
Parameters:
| this | |
| attribute |
an attribute name |
| value |
the attribute's value, or null |