def unescape_html(escaped_html_data):
    """This function unescapes an escaped HTML string.

    Args:
        escaped_html_data: str. Escaped HTML string to be unescaped.

    Returns:
        str. Unescaped HTML string.
    """
    # Replace list to unescape html strings.
    REPLACE_LIST_FOR_UNESCAPING = [
        ('&quot;', '"'),
        ('&#39;', '\''),
        ('&lt;', '<'),
        ('&gt;', '>'),
        ('&amp;', '&')
    ]
    unescaped_html_data = escaped_html_data
    for replace_tuple in REPLACE_LIST_FOR_UNESCAPING:
        unescaped_html_data = unescaped_html_data.replace(
            replace_tuple[0], replace_tuple[1])

    return unescaped_html_data