Builds the index using the specified training configuration. Required before efficient querying.
Prior to calling this, all queries will be conducted using encrypted exhaustive search.
After, they will be conducted using encrypted ANN search.
def train(self, n_lists: int = 0, batch_size: int = 2048, max_iters: int = 100, tolerance: float = 1e-6, max_memory: int = 0)