pub fn new(callback: F) -> Self {
        Self {
            callback,
            phantom: PhantomData,
        }
    }
/// Create a new instance of the `Inspect` operator that will apply
/// `callback` to each value in the input stream.
Create a new instance of the `Inspect` operator that will apply
`callback` to each value in the input stream.
Create a new instance of the ` Inspect ` operator that will apply ` callback ` to each value in the input stream .
pub fn new(callback: F) -> Self {
        Self {
            callback,
            phantom: PhantomData,
        }
    }
pub fn new ( callback : F ) -> Self { Self { callback , phantom : PhantomData , } }
Create a new instance of the `Inspect` operator that will apply
`callback` to each value in the input stream.
Create a new instance of the ` Inspect ` operator that will apply ` callback ` to each value in the input stream .
callback
F