+ @return
+ One of the following values:
+ - wxFLEX_GROWMODE_NONE: Sizer doesn't grow in the non-flexible direction.
+ - wxFLEX_GROWMODE_SPECIFIED: Sizer honors growable columns/rows set with
+ AddGrowableCol() and AddGrowableRow(). In this case equal sizing applies
+ to minimum sizes of columns or rows (this is the default value).
+ - wxFLEX_GROWMODE_ALL: Sizer equally stretches all columns or rows in
+ the non-flexible direction, whether they are growable or not in the
+ flexible direction.