@java.lang.Override
      public Builder clear() {
        super.clear();
        bitField0_ = 0;
        traceId_ = "";
        spanId_ = "";
        type_ = 0;
        attributes_ = null;
        if (attributesBuilder_ != null) {
          attributesBuilder_.dispose();
          attributesBuilder_ = null;
        }
        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