Retrieve a text node from the API

        :param textId: CtsTextMetadata Identifier
        :type textId: str
        :param subreference: CapitainsCtsPassage Reference
        :type subreference: str
        :param prevnext: Retrieve graph representing previous and next passage
        :type prevnext: boolean
        :param metadata: Retrieve metadata about the passage and the text
        :type metadata: boolean
        :return: CapitainsCtsPassage
        :rtype: CapitainsCtsPassage

def getTextualNode(
            self,
            textId: str,
            subreference: Union[str, BaseReference]=None,
            prevnext: bool=False,
            metadata: bool=False
    ) -> TextualNode:
        """ Retrieve a text node from the API

        :param textId: CtsTextMetadata Identifier
        :type textId: str
        :param subreference: CapitainsCtsPassage Reference
        :type subreference: str
        :param prevnext: Retrieve graph representing previous and next passage
        :type prevnext: boolean
        :param metadata: Retrieve metadata about the passage and the text
        :type metadata: boolean
        :return: CapitainsCtsPassage
        :rtype: CapitainsCtsPassage
        """
        raise NotImplementedError()