pub fn calculate_frame_abundances_emg_par(
time_map: &HashMap<i32, f64>,
occurrences: Vec<Vec<i32>>,
rts: Vec<f64>,
sigmas: Vec<f64>,
lambdas: Vec<f64>,
rt_cycle_length: f64,
num_threads: usize,
n_steps: Option<usize>,
) -> Vec<Vec<f64>>