int getInt16(int byteOffset, [ Endianness endian = Endianness.BIG_ENDIAN ])

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 215 and 215 - 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]);