public java.lang.String getApiVersion() {
      java.lang.Object ref = apiVersion_;
      if (!(ref instanceof java.lang.String)) {
        com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
        java.lang.String s = bs.toStringUtf8();
        apiVersion_ = s;
        return s;
      } else {
        return (java.lang.String) ref;
      }
    }
<pre>
Output only. API version used to start the operation.
</pre>

<code>string api_version = 6 [(.google.api.field_behavior) = OUTPUT_ONLY];</code>

@return The apiVersion.
java-video-live-stream/proto-google-cloud-live-stream-v1/src/main/java/com/google/cloud/video/livestream/v1/OperationMetadata.java