class_docstr: Lookahead expression.
class_docstr_tok: ["Lookahead","expression","."]
code: def __init__(self, childnode, negative=False):
      self.childnode = childnode
      self.negative = negative
  
imports: from __future__ import unicode_literals
  import re
label_desc: Use image node_id 1 to create a new Lookahead object from inherited base classes: Node with example: obj = Lookahead(childnode, negative)