set method
the long value (number from -9223372036854775808 to 9223372036854775807)
Implementation
void set(int v) {
if (v > 9007199254740991 || v < -9007199254740991) {
throw _gen.error(
'Byte must be between -9223372036854775808 and 9223372036854775807');
}
_number = v;
}