basic mapping or id
 mapping defined by the mapped superclass or embeddable class (or
 embeddable class of one of its attributes).

 <p> May be applied to an element collection containing instances of
 an embeddable class or to a map collection whose key and/or value
 is an embeddable class. When <code>AttributeOverride</code> is
 applied to a map, "<code>key.</code>" or "<code>value.</code>" must
 be used to prefix the name of the attribute that is being
 overridden in order to specify it as part of the ma