DefaultGridLayer gridLayer = new DefaultGridLayer(bodyDataProvider,
        new DefaultColumnHeaderDataProvider(columnNames, columnToLabelMap),
        new RequirementsRowHeaderDataProvider(bodyDataProvider, requirementsList), false);

public class RequirementsRowHeaderDataProvider implements IDataProvider {
  
  /**
   * The body data provider of the NatTable.
   */
  private final IDataProvider bodyDataProvider;
  
  /**
   * The list of elements that the row header will represent.
   */
  private EList<? extends NamedElement> elementList;
  
  /**
   * Data provider for the row labels of a NatTable.
   * @param bodyDataProvider
   *         The bodyDataProvider for the NatTableCreator.
   * @param elementList
   *         The list of elements that will be displayed in the NatTable.
   */
  public RequirementsRowHeaderDataProvider(
      IDataProvider bodyDataProvider, EList<? extends NamedElement> elementList) {
    this.bodyDataProvider = bodyDataProvider;
    this.elementList = elementList;
  }
  
  @Override
  public int getColumnCount() {
    return 1;
  }
  
  @Override
  public int getRowCount() {
    return this.bodyDataProvider.getRowCount();
  }

  @Override
  public Object getDataValue(int columnIndex, int rowIndex) {
    return getRowHeaderLabel(rowIndex);
  }
  
  /**
   * Gets the label for a given row header cell.
   * @param rowIndex
   *            The index of the row of the row header cell requested.
   * @return
   *             The name of the requirement associated with the given row.
   */
  public String getRowHeaderLabel(int rowIndex) {
    return elementList.get(rowIndex).getName();
  }

  @Override
  public void setDataValue(int columnIndex, int rowIndex, Object newValue) {
    //Gets the element associated with the given row.
    NamedElement element = elementList.get(rowIndex);
    
    //If no changes were made, simply return
    if (element.getName() != null && element.getName().equals(newValue)) {
      return;
    }
    
    OperationsUtil.performOperation(new EditName(element, newValue));
  }
  
}