private void ensureProjectAllowlistIsMutable() {
      if (!projectAllowlist_.isModifiable()) {
        projectAllowlist_ = new com.google.protobuf.LazyStringArrayList(projectAllowlist_);
      }
      bitField0_ |= 0x00000002;
    }
<pre>
Required. If true, expose the IndexEndpoint via private service connect.
</pre>

<code>bool enable_private_service_connect = 1 [(.google.api.field_behavior) = REQUIRED];
</code>

@return This builder for chaining.
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/PrivateServiceConnectConfig.java