Original 1:
  ha:{root} [root] entries: 5
   ha:{src1} entries: 2
    te:{key11} {val11}
    te:{key12} {val12}
   ha:{src2} entries: 2
    sy:{lnk} {/}
    te:{key21} {val21}
   ha:{dst} entries: 4
    sy:{lnk} {/}
    te:{key1} {val1}
    te:{key2} {val2}
    li:{recurse} FIRST te:{} LAST te:{}
     te:{} {r1}
     te:{} {r2}
     te:{} {r3}
   ha:{src3} entries: 2
    te:{key31} {val31}
    sy:{lnk} {foo}
   ha:{src4} entries: 2
    li:{recurse} FIRST te:{} LAST te:{}
     te:{} {R40}
     te:{} {R41}
    te:{key41} {val41}
After merg:
  ha:{root} [root] entries: 4
   ha:{src1} entries: 2
    te:{key11} {val11}
    te:{key12} {val12}
   ha:{dst} entries: 5
    sy:{lnk} {/}
    te:{key1} {val1}
    te:{key2} {val2}
    li:{recurse} FIRST te:{} LAST te:{}
     te:{} {r1}
     te:{} {r2}
     te:{} {r3}
    te:{key21} {val21}
   ha:{src3} entries: 2
    te:{key31} {val31}
    sy:{lnk} {foo}
   ha:{src4} entries: 2
    li:{recurse} FIRST te:{} LAST te:{}
     te:{} {R40}
     te:{} {R41}
    te:{key41} {val41}
