    /**
     * @brief Sets block in RAM of lcd display controller to write data to.
     *
     * Sets block in RAM of lcd display controller to write data to.
     * For ~CONTROLLER~ it uses horizontal addressing mode, while for
     * sh1106 the function uses page addressing mode.
     * Width can be specified as 0, thus the library will set the right boundary to
     * region of RAM block to the right column of the display.
     * @param x - column (left region)
     * @param y - row (top region)
     * @param w - width of the block in pixels to control
     *
     * @warning - this function initiates session (i2c or spi) and does not close it.
     *            To close session, please, call endBlock().
     */
