THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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The client support was lacking and was added in 3.3.4+ / 3.2.11+ / 3.4.0+ for all types of the clients (WebClient, JAX-RS Client Proxy and Microprofile Client). The matching property name is "expand.query.value.as.collection" and could be specified during the client instance creation, for example:
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