test_tube_svg.selectAll(".test_tube1").transition(t).style("fill-opacity", 1).end().then(function(){
          var t1 = test_tube_svg.selectAll(".test_tube0").transition().style("fill-opacity", 0).end().then(function(){
            test_tube_svg.selectAll(".test_tube2").transition().style("fill-opacity", 1).end().then(function(){
              test_tube_svg.selectAll(".test_tube1").transition(t).style("fill-opacity", 0).end().then(function(){
                test_tube_svg.selectAll(".test_tube3").transition(t).style("fill-opacity", 1).end().then(function(){
                  test_tube_svg.selectAll(".test_tube2").transition(t).style("fill-opacity", 0).end().then(function(){
                    test_tube_svg.selectAll(".test_tube4").transition(t).style("fill-opacity", 1).end().then(function(){
                      test_tube_svg.selectAll(".test_tube3").transition(t).style("fill-opacity", 0).end().then(function(){
                        test_tube_svg.selectAll(".test_tube5").transition(t).style("fill-opacity", 1).end().then(function(){
                          test_tube_svg.selectAll(".test_tube4").transition(t).style("fill-opacity", 0).end().then(function(){
                            test_tube_svg.selectAll(".test_tube6").transition(t).style("fill-opacity", 1).end().then(function(){
                              test_tube_svg.selectAll(".test_tube5").transition(t).style("fill-opacity", 0).end().then(function(){
                                test_tube_svg.selectAll(".test_tube7").transition(t).style("fill-opacity", 1)
                              })
                            })
                          })
                        })
                      })
                    })
                  })
                })
              })
            })
          })
        }
        )