code: public <T extends AmazonWebServiceRequest> T withRequestCredentialsProvider(final AWSCredentialsProvider credentialsProvider) {
          setRequestCredentialsProvider(credentialsProvider);
          @SuppressWarnings("unchecked")
          T t = (T) this;
          return t;
      }
docs: Sets the optional credentials provider to use for this request, overriding the default credentials
  provider at the client level.
  
  @param credentialsProvider
  The optional AWS security credentials provider to use for this request, overriding the
  default credentials provider at the client level.
  @return A reference to this updated object so that method calls can be chained together.