code: def test_linreg_r(self):
      result = pandas_ta.linreg(self.close, r=True)
      self.assertIsInstance(result, Series)
      self.assertEqual(result.name, "LRr_14")
  
imports: from .config import CORRELATION, CORRELATION_THRESHOLD, error_analysis, sample_data, VERBOSE
  from .context import pandas_ta
  from unittest import TestCase
  import pandas.testing
  from pandas import DataFrame, Series
  import talib
label_desc: Use image node_id 20 for calling the TestOverlap obj's underlying member method code with example usage: obj.test_linreg_r() without return types