class_docstr: Abstract base class for line-based input transformers.
class_docstr_tok: ["Abstract","base","class","for","line-based","input","transformers","."]
docstr: Send a line of input to the transformer, returning the transformed
  input or None if the transformer is waiting for more input.
  
  Must be overridden by subclasses.
  
  Implementations may raise ``SyntaxError`` if the input is invalid. No
  other exceptions may be raised.
code: def push(self, line):
      """Send a line of input to the transformer, returning the transformed
      input or None if the transformer is waiting for more input.
  
      Must be overridden by subclasses.
  
      Implementations may raise ``SyntaxError`` if the input is invalid. No
      other exceptions may be raised.
      """
      pass
  
imports: import abc
  import functools
  import re
  import tokenize
  from tokenize import untokenize, TokenError
  from io import StringIO
  from IPython.core.splitinput import LineInfo
  from IPython.utils import tokenutil
label_desc: Use image node_id 1 for calling the InputTransformer obj's underlying member method code with example usage: obj.push(line) without return types