Set an attribute value to this element. If it doesn't exists yet, it is added to the list of attributes, unless it is an namespace redefinition.
To set a namespace declaration http://www.w3.org/2000/xmlns namespace and xmlns as prefix. For default namespaces, use xmlns as name without prefix. Namespace URI will be the one provided as value.
name |
a prefixed attribute name or xmlns for default namespace declaration |
value |
a value for the attribute or URI for namespace declaration |