setInt8 method Null safety
Sets the byte at the specified
byteOffset in this object to the
two's complement binary representation of the specified
must fit in a single byte.
In other words,
value must be between -128 and 127, inclusive.
byteOffset must be non-negative, and
less than the length of this object.
void setInt8(int byteOffset, int value) => _unsupported();