code: public void setNumRows(final int rowCount) {
  		final int old = getRowCount();
  		if (old == rowCount) {
  			return;
  		}
  		this.dataVector.setSize(rowCount);
  		if (rowCount <= old) {
  			fireTableRowsDeleted(rowCount, old - 1);
  		} else {
  			justifyRows(old, rowCount);
  			fireTableRowsInserted(old, rowCount - 1);
  		}
  	}
docs: /*
  Sets the number of rows in the model. If the new size is greater than the
  current size, new rows are added to the end of the model If the new size is
  less than the current size, all rows at index <code>rowCount</code> and
  greater are discarded. <p>
  
  @param rowCount the new number of rows
  
  @see #setRowCount