code: def __buildRatio(self, values, ratioMaxLen=None):
      seqDS = dataseries.SequenceDataSeries()
      ret = ratio.Ratio(seqDS, ratioMaxLen)
      for value in values:
          seqDS.append(value)
      return ret
  
file_path: pyalgotrade/testcases/technical_ratio_test.py
imports: from .None import common
  from pyalgotrade.technical import ratio
  from pyalgotrade import dataseries
label_desc: Use image node_id 1 for calling the TestCase obj's underlying member method code with example usage: obj.__buildRatio(values, ratioMaxLen) and returns: ret