class_docstr: Remove useless local functions
  
  >>> import gast as ast
  >>> from pythran import passmanager, backend, metadata
  >>> pm = passmanager.PassManager("test")
  >>> node = ast.parse("def foo(): return 1")
  >>> _, node = pm.apply(RemoveDeadFunctions, node)
  >>> print(pm.dump(backend.Python, node))
  def foo():
      return 1
  >>> node = ast.parse("def foo(): return 1")
  >>> metadata.add(node.body[0], metadata.Local())
  >>> _, node = pm.apply(RemoveDeadFunctions, node)
  >>> print(pm.dump(backend.Python, node))
  <BLANKLINE>
code: def __init__(self):
      super(RemoveDeadFunctions, self).__init__(DefUseChains)
  
imports: from pythran.analyses import DefUseChains
  from pythran.passmanager import Transformation
  import pythran.metadata
label_desc: Use image node_id 1 to create a new RemoveDeadFunctions object from inherited base classes: Transformation with example: obj = RemoveDeadFunctions()