draw_key: Key drawing functions
Description
Each Geom has an associated function that draws the key when the geom needs
to be displayed in a legend. These are the options built into naniar.
Usage
draw_key_missing_point(data, params, size)
Arguments
data
A single row data frame containing the scaled aesthetics to
display in this key
params
A list of additional parameters supplied to the geom.
size
Width and height of key in mm.