public Shared(
     IMessagePackFormatter <T> formatter,
     MessagePackSerializerOptions options,
     int backed,
     ReadOnlyMemory <byte> offsets,
     IBigMemory backing)
 {
     Formatter = formatter ?? throw new ArgumentNullException(nameof(formatter));
     Options   = options ?? throw new ArgumentNullException(nameof(options));
     Backed    = backed;
     Backing   = backing ?? throw new ArgumentNullException(nameof(backing));
     Offsets   = offsets;
 }
 public Shared(
     MessagePackSerializerOptions options,
     int backed,
     IBigMemory backing)
     : this(
         options.Resolver.GetFormatter <T>(),
         options,
         backed,
         backing.AsMemory(
             backing.Length - (backed + 1) * sizeof(long),
             (backed + 1) * sizeof(long)),
         backing)
 {
 }
 public BigMemoryStream(IBigMemory memory)
 {
     Memory    = memory;
     _position = 0;
 }