Send_request failed to cast sequence item

UVM
,
6

In reply to ABD_91:
what i want to verify is a module of ahb to apb bridge, so the master and the slave will send the different transaction.below is the declare of apb_slv_nrdy_seq,
class apb_slv_basic_seq extends uvm_sequence #(apb_trans);

apb_trans req;
//Factory Registration
//
`uvm_object_utils(apb_slv_basic_seq)

//----------------------------------------------
// Methods
// ---------------------------------------------
// Standard UVM Methods:	
function new(string name = "apb_slv_basic_seq");
	super.new(name);
endfunction

virtual task pre_body();
	if(starting_phase != null) begin
		starting_phase.raise_objection(this);
	end
endtask

virtual task post_body();
	if(starting_phase != null) begin
		starting_phase.drop_objection(this);
	end
endtask

endclass

class apb_slv_nrdy_seq extends apb_slv_basic_seq;

//Factory Registration
//
`uvm_object_utils(apb_slv_nrdy_seq)

//----------------------------------------------
// Methods
// ---------------------------------------------
// Standard UVM Methods:	
function new(string name = "apb_slv_nrdy_seq");
	super.new(name);
endfunction

virtual task body();
	`uvm_do_with(req, {	pslverr		== 1'b0;
						nready_num 	inside {[1:5]};})
endtask

endclass