code: def setup(self, dtype):
      self.df = DataFrame(
          np.random.randn(100_000, 3),
          columns=["A", "B", "C"],
          dtype=dtype,
      )
      self.df["id1"] = pd.Series(np.random.randint(0, 10, 10000))
      self.df["id2"] = pd.Series(np.random.randint(100, 1000, 10000))
  
imports: from itertools import product
  import string
  import numpy
  import pandas
  from pandas import DataFrame, MultiIndex, date_range, melt, wide_to_long
  from pandas.api.types import CategoricalDtype
  from .pandas_vb_common import setup
label_desc: Use image node_id 1 for calling the Melt obj's underlying member method code with example usage: obj.setup(dtype) without return types