Function split_v_n_spaced 

pub fn split_v_n_spaced<const N: usize>(
    area: Rect,
    constraints: [Constraint; N],
    spacing: impl Into<Spacing>,
) -> ([Rect; N], Vec<Rect>)

Split area into stacked rows top-to-bottom, like split_v_n, but with a spacing-cell gap or overlap between every adjacent pair of panes, like split_v_spaced; see Spacing.

See split_h_n_spaced for the full behavior, including why gaps is a Vec rather than a second const-generic array; this is the same operation along the vertical axis.