How to solve mutation conflict

@Naman
thanks. one more problem… with bulk loaded to dgraph, all edge was missed, i think my schema and rdf is right.
the test schema file:

field1: string .
type A {
    field1
}
A: [uid] @reverse . 

field2: string .
type B {
    field2
}

the test rdf file:

<_:A_1> <dgraph.type> "A" .       
<_:A_1> <field1> "value1" .       
<_:A_2> <dgraph.type> "A" .       
<_:A_2> <field1> "value2" .       
                                  
<_:B_1> <dgraph.type> "B" .       
<_:B_1> <field2> "aaaaaaaaaaaa" . 
<_:B_1> <A> <_:A_1> .               

and the bulk command is:

dgraph bulk -s s.schema -f test.rdf --zero localhost:5080

after dgraph cluster up, i run a query in ratel:

{
  a(func: has(field2)){
    expand(_all_)
    {
      ~A{
        expand(_all_)
      }
      A{
        expand(_all_)
      }
    }
  }
}

but i can only see one data node B, no edge ~A and data node A.

{
  "data": {
    "a": [
      {
        "field2": "aaaaaaaaaaaa"
      }
    ]
  },
  "extensions": {
    "server_latency": {
      "parsing_ns": 215458,
      "processing_ns": 640911,
      "encoding_ns": 25487,
      "assign_timestamp_ns": 1072510,
      "total_ns": 2323218
    },
    "txn": {
      "start_ts": 233
    },
    "metrics": {
      "num_uids": {
        "_total": 1,
        "field2": 1,
        "~A": 0
      }
    }
  }
}