public long Read (long offset, char [] buffer, int offsetInBuffer, int count)
		{
			if (count > MaxLength || count > buffer.Length || 
			    count < 0 || ((offsetInBuffer + count) > buffer.Length))
				throw new ArgumentOutOfRangeException ("Parameter name: count");
			
			if (offset < 0 || offset > MaxLength)
				throw new ArgumentOutOfRangeException ("Parameter name: offset");
			
			if (offsetInBuffer < 0 || offsetInBuffer > buffer.Length)
				throw new ArgumentOutOfRangeException ("Parameter name: offsetInBuffer");
			
			if (buffer == null)
				throw new ArgumentNullException ("Parameter name: buffer");

			Array.Copy (this.buffer, offset, buffer, offsetInBuffer, count - offset);
			
			return (count - offset);
		}