method
getUint64

int getUint64(
int byteOffset,
[Endianness endian = Endianness.BIG_ENDIAN]
)

Returns the positive integer represented by the eight bytes starting at the specified byteOffset in this object, in unsigned binary form.

The return value will be between 0 and 2<sup>64</sup> - 1, inclusive.

Throws RangeError if byteOffset is negative, or byteOffset + 8 is greater than the length of this object.