text: /**
   * Copyright (c) 2015-present, Facebook, Inc.
   * All rights reserved.
   *
   * This source code is licensed under the BSD-style license found in the
   * LICENSE file in the root directory of this source tree. An additional grant
   * of patent rights can be found in the PATENTS file in the same directory.
   *
   * @polyfill
   */
  
  /* eslint-disable strict */
  
  // WARNING: This is an optimized version that fails on hasOwnProperty checks
  // and non objects. It's not spec-compliant. It's a perf optimization.
  // This is only needed for iOS 8 and current Android JSC.
  
  Object.assign = function (target, sources) {
    if (__DEV__) {
      if (target == null) {
        throw new TypeError('Object.assign target cannot be null or undefined');
      }
      if (typeof target !== 'object' && typeof target !== 'function') {
        throw new TypeError(
        'In this environment the target of assign MUST be an object.' +
        'This error is a performance optimization and not spec compliant.');
  
      }
    }
  
    for (var nextIndex = 1; nextIndex < arguments.length; nextIndex++) {
      var nextSource = arguments[nextIndex];
      if (nextSource == null) {
        continue;
      }
  
      if (__DEV__) {
        if (typeof nextSource !== 'object' &&
        typeof nextSource !== 'function') {
          throw new TypeError(
          'In this environment the sources for assign MUST be an object.' +
          'This error is a performance optimization and not spec compliant.');
  
        }
      }
  
      // We don't currently support accessors nor proxies. Therefore this
      // copy cannot throw. If we ever supported this then we must handle
      // exceptions and side-effects.
  
      for (var key in nextSource) {
        if (__DEV__) {
          var hasOwnProperty = Object.prototype.hasOwnProperty;
          if (!hasOwnProperty.call(nextSource, key)) {
            throw new TypeError(
            'One of the sources for assign has an enumerable key on the ' +
            'prototype chain. Are you trying to assign a prototype property? ' +
            'We don\'t allow it, as this is an edge case that we do not support. ' +
            'This error is a performance optimization and not spec compliant.');
  
          }
        }
        target[key] = nextSource[key];
      }
    }
  
    return target;
  };