
  [;1m-spec adler32_combine(FirstAdler, SecondAdler, SecondSize) ->[0m
  [;1m                         non_neg_integer()[0m
  [;1m                         when[0m
  [;1m                             FirstAdler :: non_neg_integer(),[0m
  [;1m                             SecondAdler :: non_neg_integer(),[0m
  [;1m                             SecondSize :: non_neg_integer().[0m

  Combines two previously computed adler32 checksums.

  This computation requires the size of the data object for the
  second checksum to be known.

  The following code:

    Y = erlang:adler32(Data1),
    Z = erlang:adler32(Y,Data2).

  assigns the same value to [;;4mZ[0m as this:

    X = erlang:adler32(Data1),
    Y = erlang:adler32(Data2),
    Z = erlang:adler32_combine(X,Y,iolist_size(Data2)).
