CLN: values is required argument in _shallow_copy_with_infer
State: closed

@TomAugspurger @jbrockmendel From looking at the code related to the discussion in https://github.com/pandas-dev/pandas/pull/22961, I noticed `_shallow_copy_with_infer` has the potential to not pass any values, which is never actually used in pandas. So a small code clean-up

Labels:
name: Clean

Comments:
Hello @jorisvandenbossche! Thanks for submitting the PR.

 - There are no PEP8 issues in the file [`pandas/core/indexes/base.py`](https://github.com/jorisvandenbossche/pandas/blob/00fc8dba6100fd1747799f4ef422864df8bed31f/pandas/core/indexes/base.py) !

 - There are no PEP8 issues in the file [`pandas/core/indexes/multi.py`](https://github.com/jorisvandenbossche/pandas/blob/00fc8dba6100fd1747799f4ef422864df8bed31f/pandas/core/indexes/multi.py) !

 - There are no PEP8 issues in the file [`pandas/core/indexes/period.py`](https://github.com/jorisvandenbossche/pandas/blob/00fc8dba6100fd1747799f4ef422864df8bed31f/pandas/core/indexes/period.py) !


LGTM
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22983?src=pr&el=h1) Report
> Merging [#22983](https://codecov.io/gh/pandas-dev/pandas/pull/22983?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/ee808033bd5c546e7439a06d2ed37b57c9e66844?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/22983/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/22983?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #22983      +/-   ##
==========================================
+ Coverage   92.18%   92.19%   +<.01%     
==========================================
  Files         169      169              
  Lines       50823    50821       -2     
==========================================
- Hits        46853    46852       -1     
+ Misses       3970     3969       -1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.6% <100%> (ø)` | :arrow_up: |
| #single | `42.36% <100%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/22983?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/indexes/multi.py](https://codecov.io/gh/pandas-dev/pandas/pull/22983/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9tdWx0aS5weQ==) | `95.45% <ø> (ø)` | :arrow_up: |
| [pandas/core/indexes/period.py](https://codecov.io/gh/pandas-dev/pandas/pull/22983/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9wZXJpb2QucHk=) | `93.66% <100%> (ø)` | :arrow_up: |
| [pandas/core/indexes/base.py](https://codecov.io/gh/pandas-dev/pandas/pull/22983/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9iYXNlLnB5) | `96.54% <100%> (+0.05%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22983?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/22983?src=pr&el=footer). Last update [ee80803...00fc8db](https://codecov.io/gh/pandas-dev/pandas/pull/22983?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).