docs: def filter_missing_X_and_y(X, y):
      """Remove rows from X and y where either contains nans."""
      y_nans = np.isnan(y)
      x_nans = np.isnan(X).any(axis=1)
      unioned_nans = np.logical_or(x_nans, y_nans)
  
      return X[~unioned_nans], y[~unioned_nans]