public Builder mergeTravelDuration(com.google.protobuf.Duration value) {
        if (travelDurationBuilder_ == null) {
          if (((bitField0_ & 0x00000002) != 0)
              && travelDuration_ != null
              && travelDuration_ != com.google.protobuf.Duration.getDefaultInstance()) {
            getTravelDurationBuilder().mergeFrom(value);
          } else {
            travelDuration_ = value;
          }
        } else {
          travelDurationBuilder_.mergeFrom(value);
        }
        if (travelDuration_ != null) {
          bitField0_ |= 0x00000002;
          onChanged();
        }
        return this;
      }
<pre>
The number of seconds required to travel to the job location from the
query location. A duration of 0 seconds indicates that the job isn't
reachable within the requested duration, but was returned as part of an
expanded query.
</pre>

<code>.google.protobuf.Duration travel_duration = 2;</code>
java-talent/proto-google-cloud-talent-v4/src/main/java/com/google/cloud/talent/v4/SearchJobsResponse.java