@java.lang.Override
      public Builder toBuilder() {
        return this == DEFAULT_INSTANCE ? new Builder() : new Builder().mergeFrom(this);
      }
<pre>
Required. The login form URL of the website.
</pre>

<code>string login_url = 3 [(.google.api.field_behavior) = REQUIRED];</code>

@return The bytes for loginUrl.
java-websecurityscanner/proto-google-cloud-websecurityscanner-v1beta/src/main/java/com/google/cloud/websecurityscanner/v1beta/ScanConfig.java