code: def to_model(self):
      return dict(
          mean=self._mean.to_dict(),
          mean_dtype=self._mean.dtype.name,
          std=self._std.to_dict(),
          std_dtype=self._std.dtype.name,
          select_col=self.select_col,
      )
  
imports: import logging
  import pandas
  from fate.arch import Context
  from ..abc.module import Module
label_desc: Use image node_id 4 for calling the StandardScaler obj's underlying member method code with example usage: obj.to_model() and returns: dict