class_docstr: Remove implicit tuple -> variable conversion.
  
  >>> import gast as ast
  >>> from pythran import passmanager, backend
  >>> node = ast.parse("def foo(): a=(1,2.) ; i,j = a")
  >>> pm = passmanager.PassManager("test")
  >>> _, node = pm.apply(NormalizeTuples, node)
  >>> print(pm.dump(backend.Python, node))
  def foo():
      a = (1, 2.0)
      i = a[0]
      j = a[1]
code: def visit_For(self, node):
      target = node.target
      if isinstance(target, ast.Tuple) or isinstance(target, ast.List):
          renamings = OrderedDict()
          self.traverse_tuples(target, (), renamings)
          if renamings:
              gtarget = self.get_new_id()
              node.target = ast.Name(
                  gtarget, node.target.ctx, None, None
              )
              for rename, state in renamings.items():
                  nnode = reduce(
                      lambda x, y: ast.Subscript(
                          x, ast.Constant(y, None), ast.Load()
                      ),
                      state,
                      ast.Name(gtarget, ast.Load(), None, None),
                  )
                  if isinstance(rename, str):
                      node.body.insert(
                          0,
                          ast.Assign(
                              [
                                  ast.Name(
                                      rename, ast.Store(), None, None
                                  )
                              ],
                              nnode,
                              None,
                          ),
                      )
                  else:
                      node.body.insert(
                          0, ast.Assign([rename], nnode, None)
                      )
  
      self.generic_visit(node)
      return node
  
imports: from pythran.analyses import Identifiers
  from pythran.passmanager import Transformation
  import gast
  from functools import reduce
  from collections import OrderedDict
  from copy import deepcopy
label_desc: Use image node_id 12 for calling the NormalizeTuples obj's underlying member method code with example usage: obj.visit_For(node) and returns: node