Bug 153853 [Regression]The bound column names must be unique within the entire table.
Regression case Regression_136421(under org.eclipse.birt.report.tests.model) failed. Expected result: Model will avoid adding a duplicate bound column name within a table.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/ModuleHandle.java
*            the output stream to which the design is written.
	 * @throws IOException
	 *             if the file cannot be written to the output stream
	 *             successfully.
	 */
	public void serialize( OutputStream out ) throws IOException
	{
		assert out != null;
		module.prepareToSave( );
		module.getWriter( ).write( out );
		module.onSave( );
	}
	/**
	 * Sets the name of the author of the design report.
	 * 
	 * @param author
	 *            the name of the author.
	 */
	public void setAuthor( String author )
	{
		try
		{
			setStringProperty( AUTHOR_PROP, author );
		}
		catch ( SemanticException e )
		{
			assert false;
		}
	}
	/**