code: public static Object extractRead(final DeviceAttribute da, final AttrDataFormat format) throws DevFailed {
  	if (da == null) {
  		throw DevFailedUtils.newDevFailed(ERROR_MSG_DA);
  	}
  	return InsertExtractFactory.getAttributeExtractor(da.getType()).extractRead(da, format);
      }
docs: Extract read values to an object for SCALAR, SPECTRUM and IMAGE
  
  @param da
  @return single value for SCALAR, array of primitives for SPECTRUM, 2D array of primitives for IMAGE
  @throws DevFailed