code: function Version(major, minor, micro, build) {
  
      if (typeof major === "number" && major % 1 === 0)
          this._major = major;
      else
          throw new Error("Invalid major version number '" + major + "'");
  
      if (typeof minor === "number" && minor % 1 === 0)
          this._minor = minor;
      else
          throw new Error("Invalid minor version number '" + minor + "'");
  
      if (typeof micro === "number" && micro % 1 === 0)
          this._micro = micro;
      else
          throw new Error("Invalid micro version number '" + micro + "'");
  
      if (typeof build === "number" && build % 1 === 0)
          this._build = build;
      else
          throw new Error("Invalid build version number '" + build + "'");
  }
docs: Representation of a four part Crosswalk version number.
  @param {Number} major
  @param {Number} minor
  @param {Number} micro
  @param {Number} build
  @constructor