code: def to_arrayref(u):
      
      if u.__class__ is node.funcall:
          try:
              if u.func_expr.props in "UR": # upd,ref
                  u.__class__ = node.arrayref
          except:
              pass
docs: To the parser, funcall is indistinguishable
      from rhs array reference.  But LHS references
      can be converted to arrayref nodes.