code: public TableOperation createLimitWithOffset(int offset, TableOperation child) {
  		SortTableOperation previousSort = validateAndGetChildSort(child);
  
  		if (offset < 0) {
  			throw new ValidationException("Offset should be greater or equal 0");
  		}
  
  		if (previousSort.getOffset() != -1) {
  			throw new ValidationException("OFFSET already defined");
  		}
  
  		return new SortTableOperation(previousSort.getOrder(), previousSort.getChild(), offset, -1);
  	}
docs: Adds offset to the underlying {@link SortTableOperation} if it is a valid one.
  
  @param offset offset to add
  @param child should be {@link SortTableOperation}
  @return valid sort operation with applied offset