Class type Chartjs.lineOptionContext
method chart : lineChart Js_of_ocaml.Js.t Js_of_ocaml.Js.readonly_propmethod dataIndex : int Js_of_ocaml.Js.readonly_propmethod dataset : 'a lineDataset Js_of_ocaml.Js.t Js_of_ocaml.Js.readonly_propmethod datasetIndex : int Js_of_ocaml.Js.readonly_prop