How do you analysis at the first time the UVM code?

UVM
1

Hi Now I’m trying to studying the UVM.
In especially, “Transaction Adapter” currently I’m trying to understand it.
But I come across some query when I’m looking the below code.
As you can see the below code, it’s not completed code. so I’d like to modify the code.

Question. When I see “apb_transfer transfer;” the below code, I’m curious where “apb_transfer” does come from.
Because to use member variable of apb_transfer, I need to what member variables are declared.
But It’s not declared in this code so it’s too hard to know. From here I want to know that if you see the code to analysis and implement, then how do you usually do to analysis the UVM code?

class reg_to_apb_adapter extends uvm_reg_adapter;

`uvm_object_utils(reg_to_apb_adapter)

  function new(string name="reg_to_apb_adapter");
    super.new(name);
  endfunction : new

  function uvm_sequence_item reg2bus(const ref uvm_reg_bus_op rw);
    apb_transfer transfer;
    transfer = apb_transfer::type_id::create("transfer");
    transfer.addr = rw.addr;
    transfer.data = rw.data;
    transfer.direction = (rw.kind == UVM_READ) ? APB_READ : APB_WRITE;
    return (transfer);
  endfunction : reg2bus

  function void bus2reg(uvm_sequence_item bus_item, ref uvm_reg_bus_op rw);
    apb_transfer transfer;
    if (!$cast(transfer, bus_item)) begin
      `uvm_fatal("NOT_REG_TYPE",
       "Provided bus_item is not of the correct type. Expecting apb_transfer")
       return;
    end
    // UVM_REG
    // LAB2A
    // finish bus2reg function 

  endfunction  : bus2reg

endclass : reg_to_apb_adapter
2

In reply to UVM_LOVE:

This code should be part of a larger UVM environment which will contain the definition of the apb_transfer sequence_item. You will need to refer to that source code to see what member variables it contains.