code: public <T> Optional<T> GET(String partialUrl, Map<String, Object> headers, 
          List<String> queryParams, GenericType<T> returnType)
      {
          URI uri = buildUri(partialUrl);
          return executeGetRequest(uri, headers, queryParams, returnType);
      }
docs: Execute a GET call against the partial URL and deserialize the results.
  @param <T> The type parameter used for the return object
  @param partialUrl The partial URL to build
  @param returnType The expected return type
  @param headers A set of headers to add to the request
  @param queryParams A set of query parameters to add to the request
  @return The return type