public Builder setSourceLanguageCode(java.lang.String value) {
        if (value == null) {
          throw new NullPointerException();
        }
        sourceLanguageCode_ = value;
        bitField0_ |= 0x00000001;
        onChanged();
        return this;
      }
<pre>
Required. The BCP-47 language code of the input text, for example,
"en-US". Expected to be an exact match for GlossaryTerm.language_code.
</pre>

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

@param value The sourceLanguageCode to set.
@return This builder for chaining.
java-translate/proto-google-cloud-translate-v3beta1/src/main/java/com/google/cloud/translate/v3beta1/Glossary.java