class_docstr: Useful commands
  - run all tests: pytest examples/orderbook_data/example.py
  - run a single test:  pytest -s --pdb --disable-warnings examples/orderbook_data/example.py::TestClass::test_basic01
class_docstr_tok: ["Useful","commands","-","run","all","tests",":","pytest","examples\/orderbook_data\/example.py","-","run","a","single","test",":","pytest","-s","--","pdb","--","disable-warnings","examples\/orderbook_data\/example.py",":",":TestClass",":",":test_basic01"]
code: def test_exp_01(self):
      exprs = []
      names = []
      for name in ["asize", "bsize"]:
          for i in range(1, 11):
              exprs.append(
                  f"TResample(${name}{i}, '1min', 'mean') / ({self.total_volume})"
              )
              names.append(f"v_{name}_{i}")
      df = D.features(self.stocks_list, fields=exprs, freq="ticks")
      df.columns = names
      print(df)
  
imports: from arctic.arctic import Arctic
  import qlib
  from qlib.data import D
  import unittest
label_desc: Use image node_id 8 for calling the TestClass obj's underlying member method code with example usage: obj.test_exp_01() without return types