How should I do when two package be dependent on each other?

In reply to dave_59:

Dave you are right. But putting the class a definition into package pa like this

package pa;
  class a extends uvm_sequence_item;
   .....
  endclass
endpackage
package pb;
  import pa::*;
  export pa::a;
<more entries>
endpackage
 
class test extends base_test;
  import pb::*;
  a aobj;
.....
endclass