public void AddHtmlAttribute(string scope, string attributeName, string attributeValue)
{
SortedDictionary<string, string> attributes = new SortedDictionary<string, string>();
if (_htmlAttributes.ContainsKey(scope))
{
attributes = new SortedDictionary<string, string>(_htmlAttributes[scope]);
}
else
{
attributes = new SortedDictionary<string, string>();
}

attributes[attributeName] = attributeValue;
_htmlAttributes[scope] = attributes;
}

i keep on receiving this error

System.ArgumentException: 'An item with the same key has already been added. Key: [body, System.Collections.Generic.SortedDictionary`2[System.String,System.String]]'