Example in the book
# modern way to do this conversion (but currently looses the CRS attribute):
map_4326 |>
st_geometry() |>
st_transform("EPSG:5356") |>
st_transform(pipeline = "+proj=unitconvert +xy_out=km")
## Geometry set for 1 feature
## Geometry type: MULTIPOLYGON
## Dimension: XY
## Bounding box: xmin: 431.3593 ymin: 7467.767 xmax: 1723.061 ymax: 8924.548
## CRS: NA
## MULTIPOLYGON (((445.7616 8064.389, 445.7457 806...