code: def visit_Name(self, node):
          
          if node.id in self.naming:
              return self.naming[node.id]
          elif node.id in self.global_declarations:
              return [frozenset([self.global_declarations[node.id]])]
          elif isinstance(node.ctx, ast.Param):
              deps = [frozenset()]
              self.naming[node.id] = deps
              return deps
          else:
              raise PythranInternalError("Variable '{}' use before assignment"
                                         "".format(node.id))
docs: Return dependencies for given variable.
  
          It have to be register first.