If the specified length is less than 128, write to this stream the one‐byte type indicator for a one‐byte integer and the one‐byte integer comprised of the least‐significant one byte of the length; otherwise, write to this stream the one‐byte type indicator for a four‐byte integer and the four‐byte, two's complement integer (in network byte order) comprised of the least‐significant four bytes of the length (in host byte order) with the most‐significant bit set. Return a reference to this stream. If this stream is initially invalid, this operation has no effect. If the next output operation has been set to be marked invalid (see makeNextInvalid), reset this marking and emit the invalid indicator instead of the type indicator. The behavior is undefined unless 0 <= length.