code: public static ProviderContext of(String provider, RateType rateType, RateType... rateTypes) {
          return ProviderContextBuilder.of(provider, rateType, rateTypes).build();
      }
docs: Creates a new ProviderContext based on the provider id and rate type(s).
  
  @param provider  the provider id, not null.
  @param rateType  the required {@link RateType}, not null.
  @param rateTypes the required {@link RateType}s, not null
  @return a new {@link ProviderContext} instance.