def _add_doc_value(self, field_name: str, jsonpath: str) -> None:
        """
        Add a value to knowledge graph by giving a jsonpath

        Args:
            field_name: str
            jsonpath: str

        Returns:
        """
        path = self.origin_doc.etk.parse_json_path(jsonpath)
        matches = path.find(self.origin_doc.value)
        all_valid = True
        invalid = []
        for a_match in matches:
            # If the value is the empty string, we treat is a None.
            if a_match.value:
                valid = self._add_value(field_name, a_match.value, provenance_path=str(a_match.full_path))
                if not valid:
                    invalid.append(field_name + ":" + str(a_match.value))
                all_valid = all_valid and valid

        if not all_valid:
            raise KgValueError("Some kg value type invalid according to schema: " + json.dumps(invalid))
Add a value to knowledge graph by giving a jsonpath

        Args:
            field_name: str
            jsonpath: str

        Returns: