How to use the vis-util.bridgeObject function in vis-util

if (typeof newOptions.fixed === 'boolean') {
        parentOptions.fixed.x = newOptions.fixed;
        parentOptions.fixed.y = newOptions.fixed;
      }
      else {
        if (newOptions.fixed.x !== undefined && typeof newOptions.fixed.x === 'boolean') {
          parentOptions.fixed.x = newOptions.fixed.x;
        }
        if (newOptions.fixed.y !== undefined && typeof newOptions.fixed.y === 'boolean') {
          parentOptions.fixed.y = newOptions.fixed.y;
        }
      }
    }

    if (allowDeletion === true && newOptions.font === null) {
      parentOptions.font =  util.bridgeObject(globalOptions.font); // set the object back to the global options
    }

    Node.updateGroupOptions(parentOptions, newOptions, groupList);

    // handle the scaling options, specifically the label part
    if (newOptions.scaling !== undefined) {
      util.mergeOptions(parentOptions.scaling, newOptions.scaling, 'label', globalOptions.scaling);
    }
  }

constructor(options, body, imagelist, grouplist, globalOptions, defaultOptions) {
    this.options = util.bridgeObject(globalOptions);
    this.globalOptions = globalOptions;
    this.defaultOptions = defaultOptions;
    this.body = body;

    this.edges = []; // all edges connected to this node

    // set defaults for the options
    this.id = undefined;
    this.imagelist = imagelist;
    this.grouplist = grouplist;

    // state options
    this.x = undefined;
    this.y = undefined;
    this.baseSize = this.options.size;
    this.baseFontSize = this.options.font.size;

'shadow'
    ];
    util.selectiveNotDeepExtend(fields, parentOptions, newOptions, allowDeletion);

    Node.checkMass(newOptions);

    // merge the shadow options into the parent.
    util.mergeOptions(parentOptions, newOptions, 'shadow', globalOptions);

    // individual shape newOptions
    if (newOptions.color !== undefined && newOptions.color !== null) {
      let parsedColor = util.parseColor(newOptions.color);
      util.fillIfDefined(parentOptions.color, parsedColor);
    }
    else if (allowDeletion === true && newOptions.color === null) {
      parentOptions.color = util.bridgeObject(globalOptions.color); // set the object back to the global options
    }

    // handle the fixed options
    if (newOptions.fixed !== undefined && newOptions.fixed !== null) {
      if (typeof newOptions.fixed === 'boolean') {
        parentOptions.fixed.x = newOptions.fixed;
        parentOptions.fixed.y = newOptions.fixed;
      }
      else {
        if (newOptions.fixed.x !== undefined && typeof newOptions.fixed.x === 'boolean') {
          parentOptions.fixed.x = newOptions.fixed.x;
        }
        if (newOptions.fixed.y !== undefined && typeof newOptions.fixed.y === 'boolean') {
          parentOptions.fixed.y = newOptions.fixed.y;
        }
      }

useImageSize: false,  // only for image and circularImage shapes
        useBorderWithImage: false  // only for image shape
      },
      size: 25,
      title: undefined,
      value: undefined,
      x: undefined,
      y: undefined
    };

    // Protect from idiocy
    if (this.defaultOptions.mass <= 0) {
      throw 'Internal error: mass in defaultOptions of NodesHandler may not be zero or negative';
    }

    this.options = util.bridgeObject(this.defaultOptions);

    this.bindEventListeners();
  }

constructor(options, body, imagelist, globalOptions, defaultOptions) {
    if (body === undefined) {
      throw new Error("No body provided");
    }

    // Since globalOptions is constant in values as well as reference,
    // Following needs to be done only once.

    this.options = util.bridgeObject(globalOptions);
    this.globalOptions = globalOptions;
    this.defaultOptions = defaultOptions;
    this.body = body;
    this.imagelist = imagelist;

    // initialize variables
    this.id = undefined;
    this.fromId = undefined;
    this.toId = undefined;
    this.selected = false;
    this.hover = false;
    this.labelDirty = true;

    this.baseWidth = this.options.width;
    this.baseFontSize = this.options.font.size;

if (colorsDefined === true) {
          toColor.inherit = false;
        } else {
          if (toColor.inherit === undefined) {
            toColor.inherit = 'from';  // Set default
          }
        }
      }
    }
    else if (allowDeletion === true && newOptions.color === null) {
      parentOptions.color = util.bridgeObject(globalOptions.color); // set the object back to the global options
    }

    if (allowDeletion === true && newOptions.font === null) {
      parentOptions.font = util.bridgeObject(globalOptions.font); // set the object back to the global options
    }
  }

if (fromColor.highlight !== undefined) {toColor.highlight = fromColor.highlight; colorsDefined = true;}
        if (fromColor.hover     !== undefined) {toColor.hover     = fromColor.hover;     colorsDefined = true;}
        if (fromColor.inherit   !== undefined) {toColor.inherit   = fromColor.inherit;}
        if (fromColor.opacity   !== undefined) {toColor.opacity   = Math.min(1,Math.max(0,fromColor.opacity));}

        if (colorsDefined === true) {
          toColor.inherit = false;
        } else {
          if (toColor.inherit === undefined) {
            toColor.inherit = 'from';  // Set default
          }
        }
      }
    }
    else if (allowDeletion === true && newOptions.color === null) {
      parentOptions.color = util.bridgeObject(globalOptions.color); // set the object back to the global options
    }

    if (allowDeletion === true && newOptions.font === null) {
      parentOptions.font = util.bridgeObject(globalOptions.font); // set the object back to the global options
    }
  }