@java.lang.Override
      public Builder mergeFrom(com.google.protobuf.Message other) {
        if (other instanceof com.google.devtools.cloudtrace.v2.Span.Link) {
          return mergeFrom((com.google.devtools.cloudtrace.v2.Span.Link) other);
        } else {
          super.mergeFrom(other);
          return this;
        }
      }
<pre>
A pointer from the current span to another span in the same trace or in a
different trace. For example, this can be used in batching operations,
where a single batch handler processes multiple requests from different
traces or when the handler receives a request from a different project.
</pre>

Protobuf type {@code google.devtools.cloudtrace.v2.Span.Link}
java-trace/proto-google-cloud-trace-v2/src/main/java/com/google/devtools/cloudtrace/v2/Span.java