def extract_measure_period_or_default(default)
      if default
        mp_low = HQMF::Value.new('TS', nil, '201201010000', nil, nil, nil)
        mp_high = HQMF::Value.new('TS', nil, '201212312359', nil, nil, nil)
        mp_width = HQMF::Value.new('PQ', 'a', '1', nil, nil, nil)
        HQMF::EffectiveTime.new(mp_low, mp_high, mp_width)
      else
        measure_period_def = @doc.at_xpath('cda:QualityMeasureDocument/cda:controlVariable/cda:measurePeriod/cda:value',
                                           NAMESPACES)
        EffectiveTime.new(measure_period_def).to_model if measure_period_def
      end
    end
def extract_measure_period_or_default(default)
      if default
        mp_low = HQMF::Value.new('TS', nil, '201201010000', nil, nil, nil)
        mp_high = HQMF::Value.new('TS', nil, '201212312359', nil, nil, nil)
        mp_width = HQMF::Value.new('PQ', 'a', '1', nil, nil, nil)
        HQMF::EffectiveTime.new(mp_low, mp_high, mp_width)
      else
        measure_period_def = @doc.at_xpath('cda:QualityMeasureDocument/cda:controlVariable/cda:measurePeriod/cda:value',
                                           NAMESPACES)
        EffectiveTime.new(measure_period_def).to_model if measure_period_def
      end
    end
Extracts a measure period from the document or returns the default measure period
  (if the default value is set to true).