code: public ArmeriaRetrofitBuilder baseUrl(String baseUrl) {
          requireNonNull(baseUrl, "baseUrl");
          final URI uri = URI.create(baseUrl);
          checkArgument(SessionProtocol.find(uri.getScheme()).isPresent(),
                        "baseUrl must have an HTTP scheme: %s", baseUrl);
          final String path = uri.getPath();
          if (!path.isEmpty() && !SLASH.equals(path.substring(path.length() - 1))) {
              throw new IllegalArgumentException("baseUrl must end with /: " + baseUrl);
          }
          this.baseUrl = baseUrl;
          return this;
      }
docs: Sets the API base URL.
  
  @see Builder#baseUrl(String)