void setStructureSize(int size) {
		if (viewComposite == null || viewComposite.isPackingEnabled()) {
			return;
		}
		int currentLength = (viewComposite.isZeroLength()) ? 0 : viewComposite.getLength();
		if (currentLength == size) {
			return;
		}

		viewDTM.withTransaction("Set Size", () -> {
			viewComposite.setLength(size);
		});
		notifyCompositeChanged();
	}
Returns an attribute value for the cell at <I>columnIndex</I>
and <I>rowIndex</I>.

@param	rowIndex	the row whose value is to be looked up
@param	columnIndex 	the column whose value is to be looked up
@return	the value Object at the specified cell
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/compositeeditor/StructureEditorModel.java