Bug 315050 [Automation][Regression]Image size is different from golden file when preview as xls
engine/org.eclipse.birt.report.engine.emitter.prototype.excel/src/org/eclipse/birt/report/engine/emitter/excel/layout/ExcelLayoutEngine.java
Data empty = createEmptyData( style );
			empty.setStartX( childStartCoordinate );
			empty.setEndX( parentEndCoordinate );
			empty.setRowIndex( data.getRowIndex( ) );
			addDatatoCache( column, empty );
			addBlankData( column - num - 1, num, empty );
		}
	}
	private void addBlankData( int column, int num, Data empty )
	{
		for ( int i = 1; i <= num; i++ )
		{
			BlankData blank = new BlankData( empty );
			blank.setRowIndex( empty.getRowIndex( ) );
			addDatatoCache( column + i, blank );
		}
	}
	private void removeRightBorder( StyleEntry style )
	{
		style.setProperty( StyleConstant.BORDER_RIGHT_COLOR_PROP, null );
		style.setProperty( StyleConstant.BORDER_RIGHT_STYLE_PROP, null );
		style.setProperty( StyleConstant.BORDER_RIGHT_WIDTH_PROP, null );
	}
	private void removeLeftBorder( StyleEntry style )
	{
		style.setProperty( StyleConstant.BORDER_LEFT_COLOR_PROP, null );
		style.setProperty( StyleConstant.BORDER_LEFT_STYLE_PROP, null );
		style.setProperty( StyleConstant.BORDER_LEFT_WIDTH_PROP, null );
	}
	private void removeDiagonalLine( StyleEntry style )