code: def simple_index(self):
      return RangeIndex(start=0, stop=20, step=2)
  
imports: import numpy
  import pytest
  from pandas.core.dtypes.common import ensure_platform_int
  import pandas
  from pandas import Index, RangeIndex
  import pandas._testing
label_desc: Use image node_id 1 for calling the TestRangeIndex obj's underlying member method code with example usage: obj.simple_index() and returns: RangeIndex