Removed duplicated _constructor_sliced definition in sparse.frame
Removal of duplicated code in core.sparse.frame
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17604?src=pr&el=h1) Report
> Merging [#17604](https://codecov.io/gh/pandas-dev/pandas/pull/17604?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/c5c3642e49f681b94d6d02ed25b25e18e05c2ef3?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/17604/graphs/tree.svg?height=150&token=eZ4WkYLtcO&width=650&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/17604?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #17604      +/-   ##
==========================================
- Coverage   91.19%   91.17%   -0.02%     
==========================================
  Files         163      163              
  Lines       49626    49625       -1     
==========================================
- Hits        45258    45248      -10     
- Misses       4368     4377       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.96% <ø> (-0.01%)` | :arrow_down: |
| #single | `40.19% <ø> (-0.07%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/17604?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/sparse/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/17604?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc3BhcnNlL2ZyYW1lLnB5) | `94.69% <ø> (-0.02%)` | :arrow_down: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/17604?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/17604?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.77% <0%> (-0.1%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17604?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/17604?src=pr&el=footer). Last update [c5c3642...1c75100](https://codecov.io/gh/pandas-dev/pandas/pull/17604?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 The one failed travis-ci build seems due to "CondaHTTPError". Restarted those workers. Thanks @avmarchenko !