Revert "Rename SecondClass to Main"

This reverts commit faad4ac4ec19219ef1a4c7d1c36fcf4d6d7b282e.
Revert "Revert "Rename SecondClass to Main""

This reverts commit 503806d3e731fefd578a928756559c21da2208a5.
Revert "Revert "Revert "Rename SecondClass to Main"""

This reverts commit afaba751e32497448ad4a9f8762909fda9898381.