def __getitem__(self, key: Union[str, int]) -> Union[numpy.ndarray, None]:
        """Retrieve a vector for a given key. Returns None if the key is not
        in the table.

        key (unicode / int): The key to look up.
        RETURNS (numpy.ndarray): The vector.
        """
        key = self.ensure_int_key(key)
        if key in self.vectors:
            return self.vectors[key]
        return None
Retrieve a vector for a given key. Returns None if the key is not
        in the table.

        key (unicode / int): The key to look up.
        RETURNS (numpy.ndarray): The vector.
        
sense2vec/sense2vec.py