@Override
  public @NotNull PsiSubstitutor put(@NotNull PsiTypeParameter classParameter, PsiType mapping){
    if (mapping != null) {
      PsiUtil.ensureValidType(mapping);
    }
    return PsiSubstitutorFactory.getInstance().createSubstitutor(classParameter, mapping);
  }
@Override
  public @NotNull PsiSubstitutor put(@NotNull PsiTypeParameter classParameter, PsiType mapping)