Shows how to use the 
ContourBuilder class to compute contour lines in an arbitrary
 rectangular array of numeric values.
 
 This example creates a 60x60 rectangular array of floating point values in the range from 0.0 to 1.0, inclusive. The
 array is displayed on the globe as an AnalyticSurface by mapping each array value to a color, where an array value of
 0.0 maps to hue 0, an array value of 1.0 maps to hue 360, and values in between are interpolated between those two
 hues. Contour lines are created at the boundaries between adjacent colors using ContourBuilder, and are displayed on
 the globe as Path shapes.