@Override
	public DataTypeComponent insert(DataType dataType) throws UsrException {
		if (hasSelection()) {
			return insert(getMinIndexSelected(), dataType);
		}
		return null;
	}
Add a DataType component into to an editable structure

@param rowIndex index to place item(s) before.
             use 0 to insert at front of a structure.
@param dataType data type to be inserted into the structure
@param dtLen the length of the data type
@param multiple number of copies of the item to be added.
@param monitor the task monitor

@throws NoSuchElementException if there is no component with the specified index.
@throws InvalidDataTypeException if the structure being edited is part
        of the data type being inserted.
@throws CancelledException if the work was cancelled
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/compositeeditor/CompEditorModel.java