You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: quant.rs
    path of file: ./repos/tract/tensorflow/src/ops
    
    the code of the file until where you have to start completion: use tract_hir::internal::*;
use tract_hir::ops;
use tract_hir::ops::math::round_ties_to_even;

use crate::model:
    
    fn step(&self, min: &Tensor, max: &Tensor) -> TractResult<f32> {
        let min = min.to_scalar::<f32>()?;
        let max = max.to_scalar::<f32>()?;
        let amplitude = max - min;
        let scale_len = 2_usize.pow(self.num_bits as u32) - 1 - self.narrow_range as usize;
        Ok(amplitude / scale_len as f32)
    }