/// <summary>
/// Gets or sets the string value of the item with the specified <code>key</code>code>.
/// </summary>
/// <param name="key">The key of the item.</param>
/// <returns>Returns the <see cref="String"/> value of the item, or <code>null</code> if not found.</returns>
public string this[string key] {
get {
IHttpPostValue value;
return _data.TryGetValue(key, out value) ? value.ToString() : null;
}
set { _data[key] = new SocialHttpPostValue(key, value); }
}
/// <summary>
/// Sets the value of the entry with specified <code>key</code>. If an entry with <code>key</code> already
/// exists, it will be overwritten.
/// </summary>
/// <param name="key">The key of the entry.</param>
/// <param name="value">The value of the entry.</param>
public void Set(string key, string value) {
_data[key] = new SocialHttpPostValue(key, value);
}