@java.lang.Override
    public final boolean isInitialized() {
      byte isInitialized = memoizedIsInitialized;
      if (isInitialized == 1) return true;
      if (isInitialized == 0) return false;

      memoizedIsInitialized = 1;
      return true;
    }
<pre>
True if break prepends the element.
</pre>

<code>bool is_prefix = 2;</code>

@return The isPrefix.
java-vision/proto-google-cloud-vision-v1/src/main/java/com/google/cloud/vision/v1/TextAnnotation.java