def METHOD_NAME(
    self, strcols: list[list[str]], index_length: int
) -> list[list[str]]:
    n_header_rows = index_length - len(self.fmt.tr_frame)
    row_num = self.fmt.tr_row_num
    for ix, col in enumerate(strcols):
        cwidth = self.adj.len(col[row_num])
        if self.fmt.is_truncated_horizontally:
            is_dot_col = ix == self._adjusted_tr_col_num
        else:
            is_dot_col = False
        if cwidth > 3 or is_dot_col:
            dots = "..."
        else:
            dots = ".."
        if ix == 0 and self.fmt.index:
            dot_mode = "left"
        elif is_dot_col:
            cwidth = 4
            dot_mode = "right"
        else:
            dot_mode = "right"
        dot_str = self.adj.justify([dots], cwidth, mode=dot_mode)[0]
        col.insert(row_num + n_header_rows, dot_str)
    return strcols