public Builder setPageToken(java.lang.String value) {
      if (value == null) {
        throw new NullPointerException();
      }
      pageToken_ = value;
      bitField0_ |= 0x00000004;
      onChanged();
      return this;
    }
<pre>
Optional. The `next_page_token` value returned from a previous
[ListBackupCollections] request, if any.
</pre>

<code>string page_token = 3 [(.google.api.field_behavior) = OPTIONAL];</code>

@param value The pageToken to set.
@return This builder for chaining.
java-valkey/proto-google-cloud-valkey-v1/src/main/java/com/google/cloud/memorystore/v1/ListBackupCollectionsRequest.java