A     (base)
|
B      inherits
|
C      inherits

##</code><code>##

         A
         |
  +---+--+---+---+
  B   C      D   E     <---------- Factory picks b,c,d or e

##</code><code>##

A     (base)
|
B     -+
|      |
C      |-- Factory can handle the chain (only B and C shown)
      -+