code: function() {
          var _this = this;
          this._adjustCenterSpringsForZoomPoint(function() {
              _this.zoomSpring.update();
          });
  
          this.centerSpringX.update();
          this.centerSpringY.update();
  
          var changed = this.centerSpringX.current.value !== this._oldCenterX ||
              this.centerSpringY.current.value !== this._oldCenterY ||
              this.zoomSpring.current.value !== this._oldZoom;
  
          this._oldCenterX = this.centerSpringX.current.value;
          this._oldCenterY = this.centerSpringY.current.value;
          this._oldZoom    = this.zoomSpring.current.value;
  
          return changed;
      }
docs: Update the zoom and center (X and Y) springs.
  @function
  @returns {Boolean} True if any change has been made, false otherwise.