public boolean hasExtensionFor(Class<?> extensionType) {
        return findFactoryFor(extensionType).isPresent();
    }
Returns true if an extension is registered for the given extension type.

@param extensionType the type to query. Must not be null
@return true if a registered extension factory handles the type
core/src/main/java/org/jdbi/v3/core/extension/Extensions.java