public Builder mergeStartOffset(com.google.protobuf.Duration value) {
        if (startOffsetBuilder_ == null) {
          if (((bitField0_ & 0x00000001) != 0)
              && startOffset_ != null
              && startOffset_ != com.google.protobuf.Duration.getDefaultInstance()) {
            getStartOffsetBuilder().mergeFrom(value);
          } else {
            startOffset_ = value;
          }
        } else {
          startOffsetBuilder_.mergeFrom(value);
        }
        if (startOffset_ != null) {
          bitField0_ |= 0x00000001;
          onChanged();
        }
        return this;
      }
<pre>
Start time offset of the partition.
</pre>

<code>.google.protobuf.Duration start_offset = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/Partition.java