code: def each(self, callback):
          
          items = self.items
  
          for item in items:
              if callback(item) is False:
                  break
  
          return self
docs: Execute a callback over each item.
  
          .. code::
  
              collection = Collection([1, 2, 3])
              collection.each(lambda x: x + 3)
  
          .. warning::
  
              It only applies the callback but does not modify the collection's items.
              Use the `transform() <#backpack.Collection.transform>`_ method to
              modify the collection.
  
          :param callback: The callback to execute
          :type callback: callable
  
          :rtype: Collection