code: def test_calmar_ratio(self):
      result = pandas_ta.calmar_ratio(self.close)
      self.assertIsInstance(result, float)
      self.assertGreaterEqual(result, 0)
  
      result = pandas_ta.calmar_ratio(self.close, years=0)
      self.assertIsNone(result)
  
      result = pandas_ta.calmar_ratio(self.close, years=-2)
      self.assertIsNone(result)
  
imports: from unittest import skip, TestCase
  from pandas import DataFrame
  from .config import sample_data
  from .context import pandas_ta
label_desc: Use image node_id 6 for calling the TestUtilityMetrics obj's underlying member method code with example usage: obj.test_calmar_ratio() without return types