/// <summary>
/// Increments (increases by n) the value of the state associated with
/// the given <paramref name="name"/> as an atomic operation or associates
/// the the specified <paramref name="name"/> with the value <paramref name="n"/>.
/// </summary>
/// <param name="states">
/// A <see cref="IAppState"/> to extend.
/// </param>
/// <param name="name">
/// The name of the state to be increased.
/// </param>
/// <param name="n">
/// The number to increment.
/// </param>
/// <exception cref="NotSupportedException">
/// The local database does not support the type <see cref="int"/>
/// </exception>
public static void Increment(this IAppState states, string name, int n)
{
states.Merge(name, n);
}