text: define(function (require) {
    var d3 = require("d3");
  
    return function (_) {
      if (typeof _ === "function") { return _; }
      if (typeof _ === "string") {
        if (_ === "time") { return d3[_].scale(); }
        if (_ === "time.utc") { return d3.time.scale.utc(); }
        return typeof d3.scale[_] === "function" ? d3.scale[_]() : d3.scale.linear();
      }
      return !_ || typeof _ !== "function" ? d3.scale.linear() : _;
    };
  });