The best way to check exists or not the session, key, value of the ini file

Hi,
I would like to check if the session, key, value of an ini file exists or not using Node-RED

[SESSION1]
KEY1=Value1
KEY2=Value2
KEY3=Value3

[SESSION2]
KEY1=Dummy1
KEY2=Dummy2

the session, key of the ini file will be predefined by chang node,
and I used the ini node to get the contents of the ini file.

After getting the contents of the ini file, apart from the function button, can combine with any other node? to check if the session, key, value of the ini file exist or not? ⇐ what I care about
※Purpose combines with other node to minimize code execution in function node.

Or to check session, key, value of the ini file exists or not, the whole all processing must be placed in the function node to execute? ⇐ I have done it

Thanks!