         diff = @choroplethMap.calculateDifference(@oldSnippetModel)
         expect(diff[0].properties[1]).to.eql(
           label: 'projection'
+          key: 'projection'
           difference: undefined
           info: "(mercator)"
         )

        diff = @choroplethMap.calculateDifference(@oldSnippetModel)
        expect(diff[3].properties[2]).to.eql
          label: 'quantize steps'
          difference: undefined
          info: '(3)'


        diff = @choroplethMap.calculateDifference(@oldSnippetModel)
        expect(diff[3].properties[0]).to.eql
          label: 'value property'
          key: 'valueProperty'
          difference: undefined
          info: '(value)'

