private void ensureTablesWrittenIsMutable() {
        if (!tablesWritten_.isModifiable()) {
          tablesWritten_ = new com.google.protobuf.LazyStringArrayList(tablesWritten_);
        }
        bitField0_ |= 0x00000100;
      }
<code>optional string operationId = 8;</code>
@param value The bytes for operationId to set.
@return This builder for chaining.
ql/src/gen/protobuf/gen-java/org/apache/hadoop/hive/ql/hooks/proto/HiveHookEvents.java