class_docstr: Default clipboard implementation.
  Just keep the data in memory.
  
  This implements a kill-ring, for Emacs mode.
code: def __init__(self, data=None, max_size=60):
      assert data is None or isinstance(data, ClipboardData)
      assert max_size >= 1
  
      self.max_size = max_size
      self._ring = deque()
      if data is not None:
          self.set_data(data)
  
imports: from .base import Clipboard, ClipboardData
  from collections import deque
label_desc: Use image node_id 1 to create a new InMemoryClipboard object from inherited base classes: Clipboard with example: obj = InMemoryClipboard(data, max_size)