private void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory,
                                      BeanDefinitionRegistry registry) {
    this.beanFactory = beanFactory;
    for (Definition definition : definitions) {
      register(beanFactory, registry, definition);
    }
  }
Create a new {@link SpockMockPostprocessor} instance with the given initial
definitions.

@param definitions the initial definitions
spock-spring/src/main/java/org/spockframework/spring/mock/SpockMockPostprocessor.java