Revert "Revert "Revert "Made the StringBuilder extension"""

This reverts commit 49c87c1ed9e4fa9d879e9a25aac653026c34bbc8.
Revert "Revert "Made the StringBuilder extension""

This reverts commit ece632a58350b9f9996b6bf8f93ec47fa7b9c022.
Revert "Revert "Revert "Made the StringBuilder extension"""

This reverts commit 49c87c1ed9e4fa9d879e9a25aac653026c34bbc8.