public Builder clearStringValue() {
      if (valueCase_ == 1) {
        valueCase_ = 0;
        value_ = null;
        onChanged();
      }
      return this;
    }
<pre>
String type value.
</pre>

<code>string string_value = 1;</code>

@return This builder for chaining.
java-visionai/proto-google-cloud-visionai-v1/src/main/java/com/google/cloud/visionai/v1/FacetValue.java