after finish the source code the senior developer check the
source code . Most of times senior developers will involved
into this code.
So this is called UTP.

Unit testing is done in bit and pieces. Like e.g. in SD 
standard order cycle; we do have 1-create order, then 2-
delivery, then 3-transfer order, then 4-PGI and then 5-
Invoice.  So we will be testing 1,2,3,4 and 5 seperately 
alone one by one using test cases and test data. We will 
not be looking and checking/testing any integration between 
order and delivery; delivery and TO; TO and PGI and then 
invoice.