Preprocesses a value from a bean configuration before the bean configurator unmarshals it into a bean property. A
common use case for such preprocessing is the evaluation of variables within the configuration value.
Preprocesses the specified bean configuration value. The optional type provided to this method is a hint (not a
requirement) for the preprocessor to resolve the value to a compatible value or a (string) value than can be
unmarshalled into that type. The preprocessor is not required to perform any type conversion but should rather
filter out incompatible values from its result.
value - The configuration value to preprocess, must not be null.
type - The target type of the value, may be null.
The processed configuration value or null if none.