/// <summary>
/// Resolves the given value against the given UnionSchema and serializes the object against
/// the resolved schema member.
/// </summary>
/// <param name="us">The UnionSchema to resolve against</param>
/// <param name="value">The value to be serialized</param>
/// <param name="encoder">The encoder for serialization</param>
private void WriteUnion(UnionSchema unionSchema, Schema[] branchSchemas, WriteItem[] branchWriters, object value, Encoder encoder)
{
int index = ResolveUnion(unionSchema, branchSchemas, value);
encoder.WriteUnionIndex(index);
branchWriters[index](value, encoder);
}
