static ResultReturner forOptionalReturn(Class<?> extensionType, Method method) {
        if (method.getReturnType() == void.class) {
            return new VoidReturner();
        }
        return forMethod(extensionType, method);
    }
If the return type is {@code void}, swallow results.

@param extensionType The extension type to use.
@param method        The method to use.
@return A {@link ResultReturner}
@see ResultReturner#forMethod(Class, Method) if the return type is not void
sqlobject/src/main/java/org/jdbi/v3/sqlobject/statement/internal/ResultReturner.java