Defines how the stroke of a pen is represented on a plot.
Created on 7 Mar 2011
Stroke basic properties
Alias for field number 2
Alias for field number 1
Alias for field number 3
Alias for field number 0
Prototypical black solid stroke Usage: StrokeBlackSolid._replace(width=2.0)
Returns SVG attributes as a dictionary from a Stroke() object.