def filter(params)
      if @filter_params
        filtered_params = {}
        params.each { |k, p| filtered_params[k] = @filter_params.include?(k.to_s) ? FILTERED_PARAM_VALUE : p }
        filtered_params
      end
    end
def filter(params)
      if @filter_params
        filtered_params = {}
        params.each { |k, p| filtered_params[k] = @filter_params.include?(k.to_s) ? FILTERED_PARAM_VALUE : p }
        filtered_params
      end
    end
Apply parameter filter

 @param [Hash] params to be filtered

 @return [Hash] filtered parameters