that only matches when the specified bean class is already
contained in the
and a single candidate can be determined.
The condition will also match if multiple matching bean instances are already contained
BeanFactory but a primary candidate has been defined; essentially, the
condition match if auto-wiring a bean with the defined type will succeed.
The condition can only match the bean definitions that have been processed by the
application context so far and, as such, it is strongly recommended to use this
condition on auto-configuration classes only. If a candidate bean may be created by
another auto-configuration, make sure that the one using this condition runs after.