public Builder clearSourceSentence() {
        sourceSentence_ = getDefaultInstance().getSourceSentence();
        bitField0_ = (bitField0_ & ~0x00000001);
        onChanged();
        return this;
      }
<pre>
Source sentence in the sentence pair.
</pre>

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

@return This builder for chaining.
java-translate/proto-google-cloud-translate-v3/src/main/java/com/google/cloud/translate/v3/AdaptiveMtTranslateRequest.java