private void ensureRegionCodesIsMutable() {
      if (!regionCodes_.isModifiable()) {
        regionCodes_ = new com.google.protobuf.LazyStringArrayList(regionCodes_);
      }
      bitField0_ |= 0x00000002;
    }
<pre>
Platform on which the threat was discovered.
</pre>

<code>.google.cloud.webrisk.v1.ThreatDiscovery.Platform platform = 1;</code>

@return This builder for chaining.
java-webrisk/proto-google-cloud-webrisk-v1/src/main/java/com/google/webrisk/v1/ThreatDiscovery.java