retrofit/src/main/java/retrofit2/Response.java
public static <T> Response<T> success(@Nullable T body, okhttp3.Response rawResponse) {
    checkNotNull(rawResponse, "rawResponse == null");
    if (!rawResponse.isSuccessful()) {
      throw new IllegalArgumentException("rawResponse must be successful response");
    }
    return new Response<>(rawResponse, body, null);
  }
public static <T> Response<T> success(@Nullable T body, okhttp3.Response rawResponse) {
    checkNotNull(rawResponse, "rawResponse == null");
    if (!rawResponse.isSuccessful()) {
      throw new IllegalArgumentException("rawResponse must be successful response");
    }
    return new Response<>(rawResponse, body, null);
  }
Create a successful response from {@code rawResponse} with {@code body} as the deserialized
body.