/// <summary>
/// Appends the value as an additional (unexpected) data-field for the instance.
/// Note that for non-repeated sub-objects, this equates to a merge operation;
/// for repeated sub-objects this adds a new instance to the set; for simple
/// values the new value supercedes the old value.
/// </summary>
/// <remarks>Note that appending a value does not remove the old value from
/// the stream; avoid repeatedly appending values for the same field.</remarks>
/// <typeparam name="TValue">The data-type of the field.</typeparam>
/// <param name="format">The data-format to use when encoding the value.</param>
/// <param name="instance">The extensible object to append the value to.</param>
/// <param name="tag">The field identifier; the tag should not be defined as a known data-field for the instance.</param>
/// <param name="value">The value to append.</param>
public static void AppendValue <TValue>(IExtensible instance, int tag, DataFormat format, TValue value)
{
ExtensibleUtil.AppendExtendValue <TValue>(instance, tag, format, value);
}
/// <summary>
/// Queries an extensible object for an additional (unexpected) data-field for the instance.
/// Each occurrence of the field is yielded separately, making this usage suitable for "repeated"
/// (list) fields.
/// </summary>
/// <remarks>The extended data is processed lazily as the enumerator is iterated.</remarks>
/// <typeparam name="TValue">The data-type of the field.</typeparam>
/// <param name="instance">The extensible object to obtain the value from.</param>
/// <param name="tag">The field identifier; the tag should not be defined as a known data-field for the instance.</param>
/// <param name="format">The data-format to use when decoding the value.</param>
/// <returns>An enumerator that yields each occurrence of the field.</returns>
public static IEnumerable <TValue> GetValues <TValue>(IExtensible instance, int tag, DataFormat format)
{
return(ExtensibleUtil.GetExtendedValues <TValue>(instance, tag, format, false, false));
}