def chain(*layers):
if len(layers) == <NUM_LIT:0>:<EOL><INDENT>return FeedForward([])<EOL><DEDENT>elif len(layers) == <NUM_LIT:1>:<EOL><INDENT>return layers[<NUM_LIT:0>]<EOL><DEDENT>else:<EOL><INDENT>return FeedForward(layers)<EOL><DEDENT>
Compose two models `f` and `g` such that they become layers of a single
    feed-forward model that computes `g(f(x))`.

    Raises exception if their dimensions don't match.