/// <summary>
/// Writes a 32 bit value as a varint. The fast route is taken when
/// there's enough buffer space left to whizz through without checking
/// for each byte; otherwise, we resort to calling WriteRawByte each time.
/// </summary>
internal void WriteRawVarint32(uint value)
{
var span = new Span <byte>(buffer);
WritingPrimitives.WriteRawVarint32(ref span, ref state, value);
}