7 classes are annotated with UbercartLineItem in Ubercart 8.4

Generic in uc_order/src/Plugin/Ubercart/LineItem/Generic.php

Handles the generic line item.

Shipping in shipping/uc_quote/src/Plugin/Ubercart/LineItem/Shipping.php

Handles the subtotal line item.

Subtotal in uc_order/src/Plugin/Ubercart/LineItem/Subtotal.php

Handles the subtotal line item.

Tax in uc_tax/src/Plugin/Ubercart/LineItem/Tax.php

Handles the tax line item.

TaxDisplay in uc_tax/src/Plugin/Ubercart/LineItem/TaxDisplay.php

Handles the tax line item.

TaxSubtotal in uc_tax/src/Plugin/Ubercart/LineItem/TaxSubtotal.php

Handles the tax line item.

Total in uc_order/src/Plugin/Ubercart/LineItem/Total.php

Handles the total line item.