public static <T> Key<T> of(Field field)
  {
    return new Key(field.getGenericType(),
                   qualifiers(field.getAnnotations()));
  }
public static < T > Key < T > of ( Field field ) { return new Key ( field . getGenericType ( ) , qualifiers ( field . getAnnotations ( ) ) ) ; }
Builds Key from field's generic type and field's qualifying annotations.
A qualifying annotation is marked with a {@code @Qualifier}.

@param field field for deriving type and annotation from
@param <T>   target type
@return instance of a Key