Chartjs.barScales
method xAxes : barAxis Js_of_ocaml.Js.t Js_of_ocaml.Js.js_array Js_of_ocaml.Js.t Js_of_ocaml.Js.prop
method yAxes : barAxis Js_of_ocaml.Js.t Js_of_ocaml.Js.js_array Js_of_ocaml.Js.t Js_of_ocaml.Js.prop