Copies this into array starting at offset.
Source
void copyIntoArray(List<num> array, [int offset = 0]) {
int i = offset;
array[i + 15] = _m4storage[15];
array[i + 14] = _m4storage[14];
array[i + 13] = _m4storage[13];
array[i + 12] = _m4storage[12];
array[i + 11] = _m4storage[11];
array[i + 10] = _m4storage[10];
array[i + 9] = _m4storage[9];
array[i + 8] = _m4storage[8];
array[i + 7] = _m4storage[7];
array[i + 6] = _m4storage[6];
array[i + 5] = _m4storage[5];
array[i + 4] = _m4storage[4];
array[i + 3] = _m4storage[3];
array[i + 2] = _m4storage[2];
array[i + 1] = _m4storage[1];
array[i + 0] = _m4storage[0];
}