private void ensureMapTypeIsMutable() {
        if (!((bitField0_ & 0x00008000) != 0)) {
          mapType_ = new java.util.ArrayList<org.apache.hadoop.hive.ql.io.protobuf.SampleProtos.MapFieldEntry>(mapType_);
          bitField0_ |= 0x00008000;
         }
      }
<code>optional bytes bytesType = 15;</code>
@return This builder for chaining.
ql/src/gen/protobuf/gen-test/org/apache/hadoop/hive/ql/io/protobuf/SampleProtos.java