Each attribute is represented as an Attribute object
Each Attribute has:
A local name, a String
A value, a String
A Namespace object (which may be 
Namespace.NO_NAMESPACE)
Everything else can be determined from these three items.
Convenience methods can convert the attribute value to various types
like int or double
JDOM enforces restrictions on attribute names and values; e.g. value may not contain < or >
Attributes are stored in a  java.util.List
in the Element that contains them
This list only contains Attribute objects.