Sets the byte at the specified
byteOffset in this object to the
unsigned binary representation of the specified
value, which must fit
in a single byte.
In other words,
value must be between 0 and 255, inclusive.
Throws RangeError if
byteOffset is negative,
or greater than or equal to the length of this object.
void setUint8(int byteOffset, int value) => _unsupported();