I want to get the near rows given one specific row. For example
give two dataframes:

```
User time
B    2
A    3

User time
A   1
B   2
A   3
D   6
E   7
G   10
D   11

```

The first one is the specific rows, and the sencond one is the whole table, let us set near window size as 1. Hence, the result show be the following:

```
User time
A   1
B   2
A   3

User time
B   2
A   3
D   6

```

but how can I get this? Thanks..