old_contents: /**
   * @fileOverview The util method based on the lodash.
   * @author dxq613@gmail.com
   * @see https://github.com/lodash/lodash
   */
  
  function _mix(dist, obj) {
    for (const k in obj) {
      if (obj.hasOwnProperty(k) && k !== 'constructor' && obj[k] !== undefined) {
        dist[k] = obj[k];
      }
    }
  }
  
  const util = {
    each: require('lodash/each'),
    isNull: require('lodash/isNull'),
    isObject: require('lodash/isObject'),
    isNumber: require('lodash/isNumber'),
    isString: require('lodash/isString'),
    lowerFirst: require('lodash/lowerFirst'),
    upperFirst: require('lodash/upperFirst'),
    isNil: require('lodash/isNil'),
    isArray: require('lodash/isArray'),
    isDate: require('lodash/isDate'),
    fixedBase(v, base) {
      const str = base.toString();
      const index = str.indexOf('.');
      if (index === -1) {
        return Math.round(v);
      }
      let length = str.substr(index + 1).length;
      if (length > 20) {
        length = 20;
      }
      return parseFloat(v.toFixed(length));
    },
    mix(dist, obj1, obj2, obj3) {
      if (obj1) {
        _mix(dist, obj1);
      }
  
      if (obj2) {
        _mix(dist, obj2);
      }
  
      if (obj3) {
        _mix(dist, obj3);
      }
      return dist;
    }
  };
  
  module.exports = util;
  
new_contents: /**
   * @fileOverview The util method based on the lodash.
   * @author dxq613@gmail.com
   * @see https://github.com/lodash/lodash
   */
  
  function _mix(dist, obj) {
    for (const k in obj) {
      if (obj.hasOwnProperty(k) && k !== 'constructor' && obj[k] !== undefined) {
        dist[k] = obj[k];
      }
    }
  }
  
  const PRECISION = 0.00001; // 常量，据的精度，小于这个精度认为是0
  
  const util = {
    each: require('lodash/each'),
    isNull: require('lodash/isNull'),
    isObject: require('lodash/isObject'),
    isNumber: require('lodash/isNumber'),
    isString: require('lodash/isString'),
    lowerFirst: require('lodash/lowerFirst'),
    upperFirst: require('lodash/upperFirst'),
    isNil: require('lodash/isNil'),
    isArray: require('lodash/isArray'),
    isDate: require('lodash/isDate'),
    fixedBase(v, base) {
      const str = base.toString();
      const index = str.indexOf('.');
      if (index === -1) {
        return Math.round(v);
      }
      let length = str.substr(index + 1).length;
      if (length > 20) {
        length = 20;
      }
      return parseFloat(v.toFixed(length));
    },
    mix(dist, obj1, obj2, obj3) {
      if (obj1) {
        _mix(dist, obj1);
      }
  
      if (obj2) {
        _mix(dist, obj2);
      }
  
      if (obj3) {
        _mix(dist, obj3);
      }
      return dist;
    },
    equal(a, b) {
      return Math.abs((a - b)) < PRECISION;
    }
  };
  
  module.exports = util;
  
subject: 添加 Util.equal(a, b) 方法。