*delete a tag this taskpaper object*

        **Key Arguments:**
            - ``tag`` -- the tag to delete to the object

        **Usage:**

            .. code-block:: python 

                aTask.del_tag("@due")

def del_tag(
            self,
            tag):
        """*delete a tag this taskpaper object*

        **Key Arguments:**
            - ``tag`` -- the tag to delete to the object

        **Usage:**

            .. code-block:: python 

                aTask.del_tag("@due")
        """

        if tag.replace("@", "") not in self.tags:
            return

        self.refresh
        oldContent = self.to_string(indentLevel=1)
        newTags = []
        newTags[:] = [n for n in newTags if tag not in n]
        self.tags = newTags
        newContent = self.to_string(indentLevel=1)

        # ADD DIRECTLY TO CONTENT IF THE PROJECT IS BEING ADDED SPECIFICALLY TO
        # THIS OBJECT
        self.parent._update_document_tree(
            oldContent=oldContent,
            newContent=newContent
        )

        self.refresh
        return None