public Builder mergeTravelDuration(com.google.protobuf.Duration value) {
      if (travelDurationBuilder_ == null) {
        if (((bitField0_ & 0x00000004) != 0)
            && travelDuration_ != null
            && travelDuration_ != com.google.protobuf.Duration.getDefaultInstance()) {
          getTravelDurationBuilder().mergeFrom(value);
        } else {
          travelDuration_ = value;
        }
      } else {
        travelDurationBuilder_.mergeFrom(value);
      }
      if (travelDuration_ != null) {
        bitField0_ |= 0x00000004;
        onChanged();
      }
      return this;
    }
<pre>
Required. The maximum travel time in seconds. The maximum allowed value is
`3600s` (one hour). Format is `123s`.
</pre>

<code>
.google.protobuf.Duration travel_duration = 3 [(.google.api.field_behavior) = REQUIRED];
</code>
java-talent/proto-google-cloud-talent-v4/src/main/java/com/google/cloud/talent/v4/CommuteFilter.java