Class type `Chartjs.barOptionContext`

method chart : barChart Js_of_ocaml.Js.t Js_of_ocaml.Js.readonly_prop
method dataIndex : int Js_of_ocaml.Js.readonly_prop
method dataset : 'a barDataset Js_of_ocaml.Js.t Js_of_ocaml.Js.readonly_prop
method datasetIndex : int Js_of_ocaml.Js.readonly_prop