def setup_variables(options = {})
        @color = (preferred_color || options.delete(:color))
        @outline = (preferred_outline || options.delete(:outline))
        @width, @height = options.delete(:size)
        @min_value, @max_value = options[:min_value], options[:max_value]
        @opacity = options[:opacity] || 1.0
        @complexity = options[:complexity]
      end
def setup_variables(options = {})
        @color = (preferred_color || options.delete(:color))
        @outline = (preferred_outline || options.delete(:outline))
        @width, @height = options.delete(:size)
        @min_value, @max_value = options[:min_value], options[:max_value]
        @opacity = options[:opacity] || 1.0
        @complexity = options[:complexity]
      end
Sets up several variables that almost every graph layer will need to render
 itself.