How to use the @antv/util.isObject function in @antv/util

private getTooltipCfg() {
    const view = this.view;
    const option = this.option;
    const theme = view.getTheme();

    const defaultCfg = get(theme, ['components', 'tooltip'], {});
    let tooltipCfg = {
      ...defaultCfg,
    };

    if (isObject(option)) {
      tooltipCfg = {
        ...defaultCfg,
        ...option,
      };
    }
    // set `crosshairs`
    const coordinate = view.getCoordinate();
    if (tooltipCfg.showCrosshairs && !tooltipCfg.crosshairs && coordinate.isRect) {
      // 目前 Tooltip 辅助线只在直角坐标系下展示
      tooltipCfg.crosshairs = !!coordinate.isTransposed ? 'y' : 'x';
    }

    if (tooltipCfg.showCrosshairs === false) {
      tooltipCfg.crosshairs = null;
    }

each(option, (value, name) => {
      const originCfg = this.get(name);
      let newCfg = value;
      if (originCfg !== value) {
        // 判断两者是否相等，主要是进行 null 的判定
        if (isObject(value) && defaultCfg[name]) {
          // 新设置的属性与默认值进行合并
          newCfg = deepMix({}, defaultCfg[name], value);
        }
        this.set(name, newCfg);
      }
    });

private addCustomLegend(field?: string): Legend {
    const viewTheme = this.theme;
    const view = this.view;
    const container = this.container.addGroup({ name: 'legend' });
    const canvas = container.get('canvas');
    const panelRange = this.panelRange;
    const legendOptions = this.options as LegendsOption;
    let fieldOption;
    if (_.isObject(legendOptions)) {
      fieldOption = legendOptions.fields ? (legendOptions.fields[field] as LegendOption) : {};
    }
    let position = fieldOption.position || legendOptions.position || viewTheme.defaultLegendPosition;
    position = this.adjustPosition(position);
    const items = fieldOption.items || legendOptions.items;
    if (!items) {
      return;
    }
    _.each(items, (item: any) => {
      if (!_.isPlainObject(item.marker)) {
        // 直接传入字符串或者回调函数时转换为对象，如 item.marker = 'circle'
        item.marker = {
          symbol: item.marker || 'circle',
          radius: MARKER_SIZE,
        };
        if (_.contains(STROKE_MARKERS, item.marker.symbol)) {

private _createAttrOption(attrName: string, field: AttributeOption | string | number, cfg?) {
    if (_.isObject(field)) {
      this._setAttrOptions(attrName, field);
    } else {
      const attrCfg: AttributeOption = {};
      if (_.isNumber(field)) {
        // size(3)
        attrCfg.values = [field];
      } else {
        attrCfg.fields = parseFields(field);
      }

      if (cfg) {
        if (_.isFunction(cfg)) {
          attrCfg.callback = cfg;
        } else {
          attrCfg.values = cfg;
        }

export function mergeTheme(themeObject: object, theme: string | object): object {
  const newThemeObject: object = isObject(theme) ? theme : getTheme(theme);

  return deepMix(themeObject, newThemeObject);
}

public parseColor() {
    const props = this.plot.options;
    const colorField = this._getColorMappingField(props);
    const config: DataPointType = {};
    if (colorField) {
      config.fields = colorField;
    }
    if (props.color) {
      if (_.isString(props.color)) {
        config.values = [props.color];
      } else if (_.isFunction(props.color)) {
        config.callback = props.color;
      } else if (_.isArray(props.color)) {
        config.values = props.color;
      } else if (_.isObject(props.color)) {
        config.fields = colorField;
        config.callback = (d) => {
          return props.color[d];
        };
      }
    }
    this.config.color = config;
  }

_.each(adjusts, (adjust, index) => {
      if (!_.isObject(adjust)) {
        adjusts[index] = { type: adjust };
      }
    });

function beforeCompare(label, condition) {
  const labelData = { [label.scaleField]: label.value };
  const con = _.clone(condition);
  if (label.type === 'time' && _.isObject(condition) && !_.isFunction(con.exp)) {
    con.exp = new Date(con.exp).getTime();
  }
  return { labelData, con };
}

each(geom.elements, (el: Element) => {
              const data = el.getModel().data;
              let value;
              if (isObject(data)) {
                value = data[field];
              } else if (isArray(data)) {
                value = data[0][field];
              }
              if (!isNil(value) && item.name === scale.getText(value)) {
                element.setState('active', enable);
              }
            });
          });