legend.RdWrapper around legend that allows adding a custom legend to a map using a keyword such as "topleft" or "bottomright". This function will place the legend in the locations within the mapped area as delineated by the axes.
add_legend(x, y, ...)The keyword to be used to position the legend (or the x coordinate)
The y coordinate to be used to position the legend (is x is also a coordinate)
arguments passed to legend