@java.lang.Override
  public int getSerializedSize() {
    int size = memoizedSize;
    if (size != -1) return size;

    size = 0;
    if (!com.google.protobuf.GeneratedMessageV3.isStringEmpty(uri_)) {
      size += com.google.protobuf.GeneratedMessageV3.computeStringSize(1, uri_);
    }
    if (pageNumber_ != 0) {
      size += com.google.protobuf.CodedOutputStream.computeInt32Size(2, pageNumber_);
    }
    size += getUnknownFields().getSerializedSize();
    memoizedSize = size;
    return size;
  }
<pre>
If the file was a PDF or TIFF, this field gives the page number within
the file used to produce the image.
</pre>

<code>int32 page_number = 2;</code>

@return The pageNumber.
java-vision/proto-google-cloud-vision-v1p3beta1/src/main/java/com/google/cloud/vision/v1p3beta1/ImageAnnotationContext.java