private void ensureBlacklistPatternsIsMutable() {
      if (!blacklistPatterns_.isModifiable()) {
        blacklistPatterns_ = new com.google.protobuf.LazyStringArrayList(blacklistPatterns_);
      }
      bitField0_ |= 0x00000040;
    }
<pre>
The user agent used during scanning.
</pre>

<code>.google.cloud.websecurityscanner.v1.ScanConfig.UserAgent user_agent = 6;</code>

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