Returns the (possibly negative) integer represented by the two bytes at
the specified byteOffset in this object, in two's complement binary
form.
The return value will be between 2<sup>15</sup> and 2<sup>15</sup> - 1, inclusive.
Throws RangeError if byteOffset is negative, or
byteOffset + 2 is greater than the length of this object.
Source
int getInt16(int byteOffset, [Endianness endian = Endianness.BIG_ENDIAN]);