Method set_box_width

Set the width of boxes in any box plots on the axes (for example [boxes()](crate::Axes2D::boxes), [box_and_whisker()](crate::Axes2D::box_and_whisker)) # Arguments `width` - Width of boxes. `is_relative` - if `true`, `width` is interpreted as a fraction of the default box width. if `false` width is an absolute value in the units of the x axis

(&mut self, width: f64, is_relative: bool)