AttributeDefinitionCollection?

I neet a list of all unit-attributes in EB's attributes folder.

Did not find an Attribute in an attribute object item inicating if this attribute is an unit attribute.

In API documentation I found the AttributeDefinitionItem class ant the AttributeDefinitionCollection class
But there is nothing like

attributedefinitions = Application.GetAttributeDefinitions.

So how to get EB's AttributeDefinitionCollection???