Provides multiple forms based on a dynamic parameter.
 
 This annotation is applied to a single parameter of a Messages subinterface
 and indicates that parameter is to be used to choose the proper form of the
 message. The parameter chosen must be of type Enum, String, boolean, or a
 primitive integral type.  This is frequently used to get proper gender for
 translations to languages where surrounding words depend on the gender of
 a person or noun.  This also marks the parameter as 
Messages.Optional.
 
 
Example:
 
   @DefaultMessage("{0} likes their widgets.")
   @AlternateMessage({
       "FEMALE", "{0} likes her widgets.",
       "MALE", "{0} likes his widgets.",
   })
   String example(String name, @Select Gender gender)