The library simplifies work with the Arduino Wire library. Talk to the device using methods that only use the device address, registry and/or value.
To see a real-life usage example, open the ADXL345 usage example, or my other projects that utilize that interface.
this->readByte(this->_I2CAddress, ADXL345_REG_ID, deviceID);
this->writeByte(this->_I2CAddress, ADXL345_POWER_CTL, registerValue);