[SPARK-28031][PYSPARK][TEST] Improve doctest on over function of Column
[SPARK-28031][PYSPARK][TEST] Improve doctest on over function of Column

## What changes were proposed in this pull request?

Just found the doctest on `over` function of `Column` is commented out. The window spec is also not for the window function used there.

We should either remove the doctest, or improve it.

Because other functions of `Column` have doctest generally, so this PR tries to improve it.

## How was this patch tested?

Added doctest.

Closes #24854 from viirya/column-test-minor.

Authored-by: Liang-Chi Hsieh <d24118b4297e1ecf0c990d6935f5f9e6e4fd7701@gmail.com>
Signed-off-by: HyukjinKwon <2680965ad5aae29275c8fb10150cb10f5554e78b@apache.org>

holdenk/spark,actuaryzhang/spark,spark-test/spark,jiangxb1987/spark,JoshRosen/spark,dbtsai/spark,maropu/spark,shuangshuangwang/spark,goldmedal/spark,nchammas/spark,kevinyu98/spark,JoshRosen/spark,cloud-fan/spark,vinodkc/spark,chuckchen/spark,kevinyu98/spark,aosagie/spark,zero323/spark,spark-test/spark,mahak/spark,taroplus/spark,HyukjinKwon/spark,actuaryzhang/spark,shuangshuangwang/spark,kiszk/spark,shuangshuangwang/spark,HyukjinKwon/spark,BryanCutler/spark,srowen/spark,actuaryzhang/spark,nchammas/spark,aosagie/spark,caneGuy/spark,caneGuy/spark,rednaxelafx/apache-spark,maropu/spark,matthewfranglen/spark,gengliangwang/spark,milliman/spark,kevinyu98/spark,taroplus/spark,zzcclp/spark,JoshRosen/spark,caneGuy/spark,zero323/spark,zzcclp/spark,zuotingbing/spark,ptkool/spark,rezasafi/spark,jiangxb1987/spark,holdenk/spark,jiangxb1987/spark,zuotingbing/spark,bdrillard/spark,rezasafi/spark,ptkool/spark,jkbradley/spark,jiangxb1987/spark,mahak/spark,nchammas/spark,actuaryzhang/spark,rezasafi/spark,shuangshuangwang/spark,skonto/spark,goldmedal/spark,kiszk/spark,hvanhovell/spark,cloud-fan/spark,jkbradley/spark,dongjoon-hyun/spark,rednaxelafx/apache-spark,maropu/spark,maropu/spark,vinodkc/spark,wangyum/spark,wzhfy/spark,dongjoon-hyun/spark,dbtsai/spark,zero323/spark,goldmedal/spark,zzcclp/spark,zuotingbing/spark,bdrillard/spark,darionyaphet/spark,WeichenXu123/spark,wangmiao1981/spark,techaddict/spark,shuangshuangwang/spark,witgo/spark,HyukjinKwon/spark,jkbradley/spark,jiangxb1987/spark,ueshin/apache-spark,kevinyu98/spark,darionyaphet/spark,chuckchen/spark,gengliangwang/spark,spark-test/spark,pgandhi999/spark,wangyum/spark,mahak/spark,hvanhovell/spark,xuanyuanking/spark,ConeyLiu/spark,hvanhovell/spark,witgo/spark,darionyaphet/spark,caneGuy/spark,HyukjinKwon/spark,caneGuy/spark,pgandhi999/spark,cloud-fan/spark,maropu/spark,aosagie/spark,rednaxelafx/apache-spark,chuckchen/spark,gengliangwang/spark,jkbradley/spark,ueshin/apache-spark,spark-test/spark,bdrillard/spark,zzcclp/spark,skonto/spark,taroplus/spark,xuanyuanking/spark,WeichenXu123/spark,xuanyuanking/spark,ConeyLiu/spark,bdrillard/spark,shaneknapp/spark,zzcclp/spark,chuckchen/spark,milliman/spark,vinodkc/spark,witgo/spark,rednaxelafx/apache-spark,cloud-fan/spark,srowen/spark,jiangxb1987/spark,ptkool/spark,pgandhi999/spark,bdrillard/spark,cloud-fan/spark,nchammas/spark,dongjoon-hyun/spark,wzhfy/spark,ptkool/spark,rednaxelafx/apache-spark,cloud-fan/spark,mahak/spark,shaneknapp/spark,spark-test/spark,JoshRosen/spark,zero323/spark,spark-test/spark,wzhfy/spark,BryanCutler/spark,rezasafi/spark,wangmiao1981/spark,zero323/spark,skonto/spark,taroplus/spark,dbtsai/spark,pgandhi999/spark,WeichenXu123/spark,bdrillard/spark,wangyum/spark,taroplus/spark,milliman/spark,maropu/spark,ueshin/apache-spark,pgandhi999/spark,dongjoon-hyun/spark,jiangxb1987/spark,BryanCutler/spark,pgandhi999/spark,jkbradley/spark,aosagie/spark,shuangshuangwang/spark,shaneknapp/spark,holdenk/spark,rezasafi/spark,pgandhi999/spark,wangmiao1981/spark,srowen/spark,apache/spark,actuaryzhang/spark,ConeyLiu/spark,kiszk/spark,dongjoon-hyun/spark,ptkool/spark,taroplus/spark,BryanCutler/spark,goldmedal/spark,HyukjinKwon/spark,mahak/spark,techaddict/spark,ConeyLiu/spark,shaneknapp/spark,apache/spark,holdenk/spark,zzcclp/spark,apache/spark,zuotingbing/spark,vinodkc/spark,dbtsai/spark,xuanyuanking/spark,shaneknapp/spark,apache/spark,nchammas/spark,witgo/spark,dbtsai/spark,darionyaphet/spark,hvanhovell/spark,kiszk/spark,xuanyuanking/spark,zuotingbing/spark,kiszk/spark,apache/spark,skonto/spark,rezasafi/spark,darionyaphet/spark,JoshRosen/spark,dbtsai/spark,witgo/spark,aosagie/spark,spark-test/spark,xuanyuanking/spark,srowen/spark,gengliangwang/spark,gengliangwang/spark,apache/spark,ueshin/apache-spark,srowen/spark,wangyum/spark,actuaryzhang/spark,BryanCutler/spark,dongjoon-hyun/spark,chuckchen/spark,nchammas/spark,jkbradley/spark,jkbradley/spark,taroplus/spark,nchammas/spark,wangmiao1981/spark,ConeyLiu/spark,milliman/spark,srowen/spark,caneGuy/spark,wzhfy/spark,skonto/spark,kevinyu98/spark,xuanyuanking/spark,vinodkc/spark,goldmedal/spark,wangyum/spark,maropu/spark,milliman/spark,witgo/spark,bdrillard/spark,actuaryzhang/spark,rezasafi/spark,wangmiao1981/spark,techaddict/spark,techaddict/spark,BryanCutler/spark,dongjoon-hyun/spark,skonto/spark,shuangshuangwang/spark,goldmedal/spark,rednaxelafx/apache-spark,ConeyLiu/spark,kevinyu98/spark,chuckchen/spark,holdenk/spark,WeichenXu123/spark,skonto/spark,zero323/spark,BryanCutler/spark,wangmiao1981/spark,rednaxelafx/apache-spark,JoshRosen/spark,zero323/spark,mahak/spark,wangmiao1981/spark,darionyaphet/spark,WeichenXu123/spark,aosagie/spark,vinodkc/spark,cloud-fan/spark,ConeyLiu/spark,shaneknapp/spark,milliman/spark,ptkool/spark,gengliangwang/spark,wzhfy/spark,WeichenXu123/spark,hvanhovell/spark,techaddict/spark,darionyaphet/spark,gengliangwang/spark,wzhfy/spark,wangyum/spark,JoshRosen/spark,vinodkc/spark,zzcclp/spark,ueshin/apache-spark,srowen/spark,ptkool/spark,chuckchen/spark,goldmed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