code: def testExample1(self):
      with common.CopyFiles(
          [os.path.join("testcases", "data", "bitstampUSD-2.csv")],
          "bitstampUSD.csv",
      ):
          code = """import sys
  sys.path.append('samples')
  import bccharts_example_1
  bccharts_example_1.main()
  """
          res = common.run_python_code(code)
          lines = common.get_file_lines("30min-bitstampUSD.csv")
          os.remove("30min-bitstampUSD.csv")
  
          # Float str doesn't behave the same in Pyhton2 and Python3.
          if six.PY3:
              lines = lines[0:1] + [
                  round_csv_line(line, 5, 8) for line in lines[1:]
              ]
  
          self.assertTrue(res.exit_ok())
          self.assertEqual(
              lines[0:10],
              common.head_file(
                  "30min-bitstampUSD-2.csv", 10, path="testcases/data"
              ),
          )
          self.assertEqual(
              lines[-10:],
              common.tail_file(
                  "30min-bitstampUSD-2.csv", 10, path="testcases/data"
              ),
          )
  
imports: import os
  import six
  from testcases import common
label_desc: Use image node_id 1 for calling the BitcoinChartsTestCase obj's underlying member method code with example usage: obj.testExample1() without return types