code: public ConfigurationAsyncClientBuilder addPolicy(HttpPipelinePolicy policy) {
          Objects.requireNonNull(policy);
          policies.add(policy);
          return this;
      }
docs: Adds a policy to the set of existing policies that are executed after
  {@link ConfigurationAsyncClient} required policies.
  
  @param policy The retry policy for service requests.
  @return The updated ConfigurationAsyncClientBuilder object.
  @throws NullPointerException If {@code policy} is {@code null}.