public Builder setPrimaryInstance(
          com.google.cloud.memorystore.v1.CrossInstanceReplicationConfig.RemoteInstance.Builder
              builderForValue) {
        if (primaryInstanceBuilder_ == null) {
          primaryInstance_ = builderForValue.build();
        } else {
          primaryInstanceBuilder_.setMessage(builderForValue.build());
        }
        bitField0_ |= 0x00000001;
        onChanged();
        return this;
      }
<pre>
Output only. The primary instance that acts as the source of replication
for the secondary instances.
</pre>

<code>
.google.cloud.memorystore.v1.CrossInstanceReplicationConfig.RemoteInstance primary_instance = 1 [(.google.api.field_behavior) = OUTPUT_ONLY];
</code>
java-valkey/proto-google-cloud-valkey-v1/src/main/java/com/google/cloud/memorystore/v1/CrossInstanceReplicationConfig.java