The method obj.getAttributeDelegate().hasAttributeByName("some:attribute:that:must:exist") returns a stacktrace if the attribute name doesn't exist. This makes it less fault tolerant, and requires callers to look up the defName by name anyway, or else add a try/catch. If there were a version that had a parameter exceptionIfAttributeNotExist or something, you could optionally just always return false if the attribute hasn't been created yet.

This is for customers rolling out customizations, to reduce the tight coupling between components as they are being deployed at different times.