public com.google.protobuf.ByteString getStrValueBytes() {
    java.lang.Object ref = "";
    if (valueCase_ == 3) {
      ref = value_;
    }
    if (ref instanceof java.lang.String) {
      com.google.protobuf.ByteString b =
          com.google.protobuf.ByteString.copyFromUtf8((java.lang.String) ref);
      if (valueCase_ == 3) {
        value_ = b;
      }
      return b;
    } else {
      return (com.google.protobuf.ByteString) ref;
    }
  }
<pre>
Value of string type annotation.
</pre>

<code>string str_value = 3;</code>

@return The bytes for strValue.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/AnnotationValue.java