Reference TBufferStream

  TBufferStream = class(TStream)
  public
    { Create a new buffer stream given a buffer }
    constructor Create(Buffer: TBuffer);
    { Read bytes from the buffer }
    function Read(var Buffer; Count: LongInt): LongInt; override;
    { Write bytes to the buffer growing it if needed }
    function Write(const Buffer; Count: LongInt): LongInt; override;
    { Move the stream position }
    function Seek(const Offset: Int64; Origin: TSeekOrigin): Int64; override;
    { Save the buffer contents to another stream }
    procedure SaveToStream(Stream: TStream);
    { Save the buffer contents to a file }
    procedure SaveToFile(const FileName: string);
  end;