docstr: Display as HTML for IPython notebook.
docstr_tok: ["Display","as","HTML","for","IPython","notebook","."]
code: def _repr_html_(self) -> str:
      """Display as HTML for IPython notebook."""
      return self.summary().as_html()
  
imports: from __future__ import annotations
  from typing import Any, NamedTuple, cast
  import pandas
  from statsmodels.iolib.summary import Summary
  from statsmodels.regression.linear_model import OLS, RegressionResults
  import arch.covariance.kernel
  from arch.typing import ArrayLike1D, ArrayLike2D, UnitRootTrend
  from arch.utility.array import ensure1d, ensure2d
  from arch.utility.timeseries import add_trend
label_desc: Use image node_id 8 for calling the ResidualCointegrationTestResult obj's underlying member method code with example usage: obj._repr_html_() and returns: self