public Builder setStart(com.google.cloud.visionai.v1.FacetValue value) {
        if (startBuilder_ == null) {
          if (value == null) {
            throw new NullPointerException();
          }
          start_ = value;
        } else {
          startBuilder_.setMessage(value);
        }
        bitField0_ |= 0x00000001;
        onChanged();
        return this;
      }
<pre>
Start of the range. Non-existence indicates some bound (e.g. -inf).
</pre>

<code>.google.cloud.visionai.v1.FacetValue start = 1;</code>
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/FacetBucket.java