List<HandlerFactory> getFactories() {
        return factories;
    }
Registry for {@link HandlerFactory handler factories}, which produce {@link Handler handlers} for SQL object methods.
By default, a factory is registered for methods annotated
with SQL annotations such as {@code @SqlUpdate} or {@code SqlQuery}. Clients may register additional factories to provide
support for other use cases. In the case that two or more registered factories would support a particular SQL object
method, the last-registered factory takes precedence.

@deprecated Use {@link ExtensionHandlerFactory} instances that are returned
from the {@link org.jdbi.v3.core.extension.ExtensionFactory#getExtensionHandlerFactories(ConfigRegistry)} method.
sqlobject/src/main/java/org/jdbi/v3/sqlobject/Handlers.java