def abbreviate(content):
    """
    Truncates content below 20 characters. Adds '...' if the content has been
    truncated.

    Examples:
        >>> abbreviate('Hey, I just met you, and this is crazy')
        'Hey, I just met you,...'
    """
    content = str(content)
    content_length = len(content)
    return content[:20].rstrip() + ("..." if content_length > 20 else "")