private com.google.protobuf.SingleFieldBuilderV3<
              com.google.cloud.storagebatchoperations.v1.PrefixList,
              com.google.cloud.storagebatchoperations.v1.PrefixList.Builder,
              com.google.cloud.storagebatchoperations.v1.PrefixListOrBuilder>
          getPrefixListFieldBuilder() {
        if (prefixListBuilder_ == null) {
          if (!(objectConfigurationCase_ == 2)) {
            objectConfiguration_ =
                com.google.cloud.storagebatchoperations.v1.PrefixList.getDefaultInstance();
          }
          prefixListBuilder_ =
              new com.google.protobuf.SingleFieldBuilderV3<
                  com.google.cloud.storagebatchoperations.v1.PrefixList,
                  com.google.cloud.storagebatchoperations.v1.PrefixList.Builder,
                  com.google.cloud.storagebatchoperations.v1.PrefixListOrBuilder>(
                  (com.google.cloud.storagebatchoperations.v1.PrefixList) objectConfiguration_,
                  getParentForChildren(),
                  isClean());
          objectConfiguration_ = null;
        }
        objectConfigurationCase_ = 2;
        onChanged();
        return prefixListBuilder_;
      }
<pre>
Specifies objects matching a prefix set.
</pre>

<code>.google.cloud.storagebatchoperations.v1.PrefixList prefix_list = 2;</code>
java-storagebatchoperations/proto-google-cloud-storagebatchoperations-v1/src/main/java/com/google/cloud/storagebatchoperations/v1/BucketList.java