border, border_left, border_right, border_top, border_bottom,
border_cm, border_left_cm, border_right_cm, border_top_cm, border_bottom_cm,
border_inch, border_left_inch, border_right_inch, border_top_inch, border_bottom_inch:
When a border is specified, map data in the specified width is added around the map.
Different values can also be specified for the right and left-hand margins, as well as for the top and bottom margins.
These values can be entered in pixel, cm or inch.
Combinations of border and border_left or border_right etc. result in an error.
It is not possible to combine pixel, cm, and inch values.