public final int getNumber() {
      if (this == UNRECOGNIZED) {
        throw new java.lang.IllegalArgumentException(
            "Can't get the number of an unknown enum value.");
      }
      return value;
    }
<pre>
Indicates that the span covers the client-side wrapper around an RPC or
other remote request.
</pre>

<code>RPC_CLIENT = 2;</code>
java-trace/proto-google-cloud-trace-v1/src/main/java/com/google/devtools/cloudtrace/v1/TraceSpan.java