code: def testSlopeBounded(self):
      slope = self.__buildSlope([1, 2, 3, 2, 1], 3, 2)
      self.assertEqual(slope[0], 0.0)
      self.assertEqual(slope[1], -1.0)
  
file_path: pyalgotrade/testcases/technical_trend_test.py
imports: from .None import common
  from pyalgotrade.technical import linreg
  from pyalgotrade import dataseries
label_desc: Use image node_id 3 for calling the SlopeTest obj's underlying member method code with example usage: obj.testSlopeBounded() without return types