@java.lang.Override
  public java.lang.String getTraceId() {
    java.lang.Object ref = traceId_;
    if (ref instanceof java.lang.String) {
      return (java.lang.String) ref;
    } else {
      com.google.protobuf.ByteString bs = (com.google.protobuf.ByteString) ref;
      java.lang.String s = bs.toStringUtf8();
      traceId_ = s;
      return s;
    }
  }
<pre>
Required. ID of the trace to return.
</pre>

<code>string trace_id = 2 [(.google.api.field_behavior) = REQUIRED];</code>

@return The traceId.
java-trace/proto-google-cloud-trace-v1/src/main/java/com/google/devtools/cloudtrace/v1/GetTraceRequest.java