Function render 

pub fn render<P, F>(
    plugin: &mut P,
    sample_rate: f64,
    num_frames: usize,
    generator: F,
) -> Result<Rendered>
where
    P: PluginCore + Plugin<f32>,
    F: FnMut(usize, usize) -> f32,

Render num_frames of a generated input through plugin. generator is called per (channel, frame) and returns the input sample at that position.

Errors

Propagates activate and process failures.