code: public void setColumns(final Integer cols) {
  		if (cols != null && cols < 0) {
  			throw new IllegalArgumentException("Must have zero or more columns");
  		}
  		Integer currColumns = getColumns();
  		if (!Objects.equals(cols, currColumns)) {
  			getOrCreateComponentModel().cols = cols;
  		}
  	}
docs: Sets the layout of uploaded files to be a certain number of columns. Null uses the theme default.
  
  @param cols the number of columns.