def get_metadata(self, key) -> str:
        """
        Get the value of a metadata. Returns None if metadata does not exist.

        Args:
          key (str): name of the metadata

        Returns:
          str: the value of the metadata (or None)

        """
        return self.metadata[key] if key in self.metadata else None
def get_metadata ( self , key ) -> str : return self . metadata [ key ] if key in self . metadata else None
Get the value of a metadata. Returns None if metadata does not exist.

        Args:
          key (str): name of the metadata

        Returns:
          str: the value of the metadata (or None)