红帽全球峰会139.3.2. 来自 head 的 readonce 示例：
Java DSL：
from("direct:get")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.READ_ONCE_HEAD))
.toF("hazelcast-%sbar", HazelcastConstants.RINGBUFFER_PREFIX)
.to("seda:out");
from("direct:get")
.setHeader(HazelcastConstants.OPERATION, constant(HazelcastOperation.READ_ONCE_HEAD))
.toF("hazelcast-%sbar", HazelcastConstants.RINGBUFFER_PREFIX)
.to("seda:out");
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