public Builder mergeFrom(com.google.devtools.cloudtrace.v2.Span.Link other) {
        if (other == com.google.devtools.cloudtrace.v2.Span.Link.getDefaultInstance()) return this;
        if (!other.getTraceId().isEmpty()) {
          traceId_ = other.traceId_;
          bitField0_ |= 0x00000001;
          onChanged();
        }
        if (!other.getSpanId().isEmpty()) {
          spanId_ = other.spanId_;
          bitField0_ |= 0x00000002;
          onChanged();
        }
        if (other.type_ != 0) {
          setTypeValue(other.getTypeValue());
        }
        if (other.hasAttributes()) {
          mergeAttributes(other.getAttributes());
        }
        this.mergeUnknownFields(other.getUnknownFields());
        onChanged();
        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