code: public static LocalFilter fromOptionalParams(List<Param> optionalParams) {
  		LocalFilter filter = new LocalFilter();
  		Param p = filter.getQueryParam(optionalParams);
  
  		if (p == null) {
  			return null;
  		}
  
  		filter.value = p.getValue();
  		return filter;
  	}
docs: Builds the LocalFilter from the array of optional Params of the
  {@link DescribeService}
  
  @param optionalParams
  @return