it("should return formatter from formatters dict when name is in formatters", () => {
      const f1 = tmpl.get_formatter("x", "@x", "$0.00", {"x": "numeral"})
      expect(f1).to.be.equal(tmpl.DEFAULT_FORMATTERS["numeral"])

      const f2 = tmpl.get_formatter("x", "@x", "%5.3f mu", {"x": "printf"})
      expect(f2).to.be.equal(tmpl.DEFAULT_FORMATTERS["printf"])

      const f3 = tmpl.get_formatter("x", "@x", "%m/%d/%Y", {"x": "datetime"})
      expect(f3).to.be.equal(tmpl.DEFAULT_FORMATTERS["datetime"])

      const custom = new CustomJSHover({code:"return format + ' ' + special_vars.special + ' ' + value"})
      const f4 = tmpl.get_formatter("x", "@x", "custom", {"x": custom})
      expect(f4(3.123, "custom", {special: 10})).to.be.equal("custom 10 3.123")
    })

 expect(() => tmpl.get_formatter("x", "@x", "%5.3f mu", {"x": "junk" as any})).to.throw(Error)