class_docstr: Optional base class for fixers.
  
  The subclass name must be FixFooBar where FooBar is the result of
  removing underscores and capitalizing the words of the fix name.
  For example, the class name for a fixer named 'has_key' should be
  FixHasKey.
class_docstr_tok: ["Optional","base","class","for","fixers",".","The","subclass","name","must","be","FixFooBar","where","FooBar","is","the","result","of","removing","underscores","and","capitalizing","the","words","of","the","fix","name",".","For","example",",","the","class","name","for","a","fixer","named","'has_key","'","should","be","FixHasKey","."]
docstr: Returns the transformation for a given parse tree node.
  
  Args:
    node: the root of the parse tree that matched the fixer.
    results: a dict mapping symbolic names to part of the match.
  
  Returns:
    None, or a node that is a modified copy of the
    argument node.  The node argument may also be modified in-place to
    effect the same change.
  
  Subclass *must* override.
docstr_tok: ["Returns","the","transformation","for","a","given","parse","tree","node",".","Args",":","node",":","the","root","of","the","parse","tree","that","matched","the","fixer",".","results",":","a","dict","mapping","symbolic","names","to","part","of","the","match",".","Returns",":","None",",","or","a","node","that","is","a","modified","copy","of","the","argument","node",".","The","node","argument","may","also","be","modified","in-place","to","effect","the","same","change",".","Subclass","*","must","*","override","."]
code: def transform(self, node, results):
      """Returns the transformation for a given parse tree node.
  
      Args:
        node: the root of the parse tree that matched the fixer.
        results: a dict mapping symbolic names to part of the match.
  
      Returns:
        None, or a node that is a modified copy of the
        argument node.  The node argument may also be modified in-place to
        effect the same change.
  
      Subclass *must* override.
      """
      raise NotImplementedError()
  
imports: import itertools
  from .patcomp import PatternCompiler
  from .None import pygram
  from .fixer_util import does_tree_import
label_desc: Use image node_id 5 for calling the BaseFix obj's underlying member method code with example usage: obj.transform(node, results) without return types