def prefer_non_nil_variables pins
      result = []
      nil_pins = []
      pins.each do |pin|
        if pin.variable? && pin.nil_assignment?
          nil_pins.push pin
        else
          result.push pin
        end
      end
      result + nil_pins
    end
def prefer_non_nil_variables pins
      result = []
      nil_pins = []
      pins.each do |pin|
        if pin.variable? && pin.nil_assignment?
          nil_pins.push pin
        else
          result.push pin
        end
      end
      result + nil_pins
    end
Sort an array of pins to put nil or undefined variables last.

 @param pins [Array<Solargraph::Pin::Base>]
 @return [Array<Solargraph::Pin::Base>]