The code provides Python wrappers around TensorFlow ops for decoding LibSVM input to tensors. To use it

Input: call the `decode_libsvm` function with the following arguments: `input` (a `Tensor` of type `string`)

Output: `num_features` (an `int` that is `>= 1`)

Prompt: `dtype` (an optional `tf.DType` from: `tf.float32