code: def testHurstExpFunMeanRev(self):
      values = (np.random.randn(50000)) + 1000
      h = hurst.hurst_exp(np.log10(values), 2, 20)
      self.assertEquals(round(h), 0)
  
file_path: pyalgotrade/testcases/technical_hurst_test.py
imports: import numpy
  from .None import common
  from pyalgotrade.technical import hurst
  from pyalgotrade import dataseries
label_desc: Use image node_id 3 for calling the TestCase obj's underlying member method code with example usage: obj.testHurstExpFunMeanRev() without return types