code: public CorsServiceBuilder preflightResponseHeader(CharSequence name, Object... values) {
          firstPolicyBuilder.preflightResponseHeader(name, values);
          return this;
      }
docs: Returns HTTP response headers that should be added to a CORS preflight response.
  
  <p>An intermediary like a load balancer might require that a CORS preflight request
  have certain headers set. This enables such headers to be added.
  
  @param name the name of the HTTP header.
  @param values the values for the HTTP header.
  @return {@link CorsServiceBuilder} to support method chaining.