swOperation/node_modules/@antv/util/src/keys.ts

import each from './each';
import isFunction from './is-function';

const keys = Object.keys ? obj => Object.keys(obj) : obj => {
  const result = [];
  each(obj, (value, key) => {
    if (!(isFunction(obj) && key === 'prototype')) {
      result.push(key);
    }
  });
  return result;
};

export default keys;