code: def test_rename_not_unique(self):
      with self.assertRaisesRegex(
          ValueError, "attempted to rename 'b' and 'c' both to 'x'"
      ):
          hl.tstruct(a=hl.tbool, b=hl.tint32, c=hl.tint32)._rename(
              {"b": "x", "c": "x"}
          )
      with self.assertRaisesRegex(
          ValueError, "attempted to rename 'a' and 'b' both to 'a'"
      ):
          hl.tstruct(a=hl.tbool, b=hl.tint32)._rename({"b": "a"})
  
imports: from typing import Optional
  import unittest
  from hail.expr import coercer_from_dtype
  from hail.expr.types import *
  from hail.genetics import reference_genome
  from ..helpers import *
  from hail.utils.java import Env
label_desc: Use image node_id 9 for calling the Tests obj's underlying member method code with example usage: obj.test_rename_not_unique() without return types