def METHOD_NAME(self) -> str:
    if self._content.text:
        return self._error_template(
            self._content.name, self._content.description or "", self._content.text
        )
    if self._content.embedded_data is None:
        return self._message_template()
    # Embed data in the message
    df = self._content.embedded_data
    # Flatten columns/index so they show up nicely in the table
    df.columns = [
        " ".join(str(name) for name in column).strip()
        if isinstance(column, tuple)
        else column
        for column in df.columns
    ]
    df.index = [
        " ".join(str(name) for name in index).strip()
        if isinstance(index, tuple)
        else index
        for index in df.index
    ]
    # Slack Markdown only works on messages shorter than 4k chars, so we might
    # need to truncate the data
    for i in range(len(df) - 1):
        truncated_df = df[: i + 1].fillna("")
        truncated_row = pd.Series({k: "..." for k in df.columns})
        truncated_df = pd.concat(
            [truncated_df, truncated_row.to_frame().T], ignore_index=True
        )
        tabulated = df.to_markdown()
        table = f"```\n{tabulated}\n```\n\n(table was truncated)"
        message = self._message_template(table)
        if len(message) > MAXIMUM_MESSAGE_SIZE:
            # Decrement i and build a message that is under the limit
            truncated_df = df[:i].fillna("")
            truncated_row = pd.Series({k: "..." for k in df.columns})
            truncated_df = pd.concat(
                [truncated_df, truncated_row.to_frame().T], ignore_index=True
            )
            tabulated = df.to_markdown()
            table = (
                f"```\n{tabulated}\n```\n\n(table was truncated)"
                if len(truncated_df) > 0
                else ""
            )
            break
    # Send full data
    else:
        tabulated = df.to_markdown()
        table = f"```\n{tabulated}\n```"
    return self._message_template(table)