public Builder setTrackingId(java.lang.String value) {
      if (value == null) {
        throw new NullPointerException();
      }
      trackingId_ = value;
      bitField0_ |= 0x00000400;
      onChanged();
      return this;
    }
<pre>
Output only. The tracking ID uniquely identifies a vulnerability instance across
multiple ScanRuns.
</pre>

<code>string tracking_id = 10;</code>

@param value The trackingId to set.
@return This builder for chaining.
java-websecurityscanner/proto-google-cloud-websecurityscanner-v1/src/main/java/com/google/cloud/websecurityscanner/v1/Finding.java