public com.google.protobuf.TimestampOrBuilder getUpdateTimeOrBuilder() {
    if (conditionTypeCase_ == 2) {
      return (com.google.protobuf.Timestamp) conditionType_;
    }
    return com.google.protobuf.Timestamp.getDefaultInstance();
  }
public com . google . protobuf . TimestampOrBuilder getUpdateTimeOrBuilder ( ) { if ( conditionTypeCase_ == 2 ) { return ( com . google . protobuf . Timestamp ) conditionType_ ; } return com . google . protobuf . Timestamp . getDefaultInstance ( ) ; }
<pre>
When set, the target document must exist and have been last updated at
that time.
</pre>

<code>.google.protobuf.Timestamp update_time = 2;</code>