public Builder clearStartOffset() {
      bitField0_ = (bitField0_ & ~0x00000001);
      startOffset_ = null;
      if (startOffsetBuilder_ != null) {
        startOffsetBuilder_.dispose();
        startOffsetBuilder_ = null;
      }
      onChanged();
      return this;
    }
<pre>
Optional. The start offset of the video.
</pre>

<code>.google.protobuf.Duration start_offset = 1 [(.google.api.field_behavior) = OPTIONAL];
</code>
java-vertexai/proto-google-cloud-vertexai-v1/src/main/java/com/google/cloud/vertexai/api/VideoMetadata.java