private com.google.protobuf.RepeatedFieldBuilderV3<
            com.google.cloud.vision.v1.Block,
            com.google.cloud.vision.v1.Block.Builder,
            com.google.cloud.vision.v1.BlockOrBuilder>
        getBlocksFieldBuilder() {
      if (blocksBuilder_ == null) {
        blocksBuilder_ =
            new com.google.protobuf.RepeatedFieldBuilderV3<
                com.google.cloud.vision.v1.Block,
                com.google.cloud.vision.v1.Block.Builder,
                com.google.cloud.vision.v1.BlockOrBuilder>(
                blocks_, ((bitField0_ & 0x00000008) != 0), getParentForChildren(), isClean());
        blocks_ = null;
      }
      return blocksBuilder_;
    }
<pre>
List of blocks of text, images etc on this page.
</pre>

<code>repeated .google.cloud.vision.v1.Block blocks = 4;</code>
java-vision/proto-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/Page.java