public Builder mergePrimaryInstance(
          com.google.cloud.memorystore.v1.CrossInstanceReplicationConfig.RemoteInstance value) {
        if (primaryInstanceBuilder_ == null) {
          if (((bitField0_ & 0x00000001) != 0)
              && primaryInstance_ != null
              && primaryInstance_
                  != com.google.cloud.memorystore.v1.CrossInstanceReplicationConfig.RemoteInstance
                      .getDefaultInstance()) {
            getPrimaryInstanceBuilder().mergeFrom(value);
          } else {
            primaryInstance_ = value;
          }
        } else {
          primaryInstanceBuilder_.mergeFrom(value);
        }
        if (primaryInstance_ != null) {
          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