public Builder clearKey() {
      key_ = getDefaultInstance().getKey();
      bitField0_ = (bitField0_ & ~0x00000001);
      onChanged();
      return this;
    }
<pre>
A unique key for this input. Must be specified when using advanced
mapping and edit lists.
</pre>

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

@return This builder for chaining.
java-video-transcoder/proto-google-cloud-video-transcoder-v1/src/main/java/com/google/cloud/video/transcoder/v1/Input.java