Bug 152430 Key can modify to empty string
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ResultSetColumnHandle.java
{
	/**
	 * Constructs the handle of result set column.
	 * 
	 * @param valueHandle
	 *            the value handle for result set column list of one property
	 * @param index
	 *            the position of this result set column in the list
	 */
	public ResultSetColumnHandle( SimpleValueHandle valueHandle, int index )
	{
		super( valueHandle, index );
	}
	/**
	 * Returns the column name.
	 * 
	 * @return the column name
	 */
	public String getColumnName( )
	{
		return getStringProperty( ResultSetColumn.NAME_MEMBER );
	}
	/**
	 * Sets the column name.
	 * 
	 * @param columnName