getInt64 abstract method
The (possibly negative) integer represented by the eight bytes at
the specified byteOffset
in this object, in two's complement binary
form.
The return value will be between -263 and 263 - 1, inclusive.
The byteOffset
must be non-negative, and
byteOffset + 8
must be less than or equal to the length of this object.
Implementation
int getInt64(int byteOffset, [Endian endian = Endian.big]);