a constructor for the target class, passing in as arguments
 values from the specified columns.  All columns corresponding
 to arguments of the intended constructor must be specified using the
 <code>columns</code> element of the <code>ConstructorResult</code>
 annotation in the same order as that of the argument list of the
 constructor.  Any entities returned as constructor results will be
 in either the new or detached state, depending on whether a primary
 key is retrieved for the constructed object.
 
