def params
      {}.
      merge!(measurable_params).
      merge!(custom_dimensions).
      merge!(custom_metrics).
      reject {|_,v| v.nil?}
    end
def params
      {}.
      merge!(measurable_params).
      merge!(custom_dimensions).
      merge!(custom_metrics).
      reject {|_,v| v.nil?}
    end
collects the parameters from options for this measurement
 @return [Hash]