code: public function setPath($path, $value)
      {
          Deprecated::method(1.1, MutableBag::class);
  
          Arr::set($this->items, $path, $value);
      }
docs: Sets a value using path syntax to set nested data.
  Inner arrays will be created as needed to set the value.
  
  Example:
  
  // Set an item at a nested structure
  $bag->setPath('foo/bar', 'color');
  
  // Append to a list in a nested structure
  $bag->get($data, 'foo/baz');
  // => null
  $bag->setPath('foo/baz/[]', 'a');
  $bag->setPath('foo/baz/[]', 'b');
  $bag->getPath('foo/baz');
  // => ['a', 'b']
  
  This function does not support keys that contain `/` or `[]` characters
  because these are special tokens used when traversing the data structure.
  A value may be appended to an existing array by using `[]` as the final
  key of a path.
  
  <br>
  Note: To set values in arrays that are in `ArrayAccess` objects their
  `offsetGet()` method needs to be able to return arrays by reference.
  See {@see MutableBag} for an example of this.
  
  @param string $path  The path to traverse and set the value at
  @param mixed  $value The value to set
  
  @throws \RuntimeException when trying to set a path that travels through a scalar value
  @throws \RuntimeException when trying to set a value in an array that is in an `ArrayAccess` object
  which cannot retrieve arrays by reference
  
  @deprecated since 1.1 and will be removed in 2.0. Use {@see MutableBag} instead.