public Builder clearCustomClassId() {
      customClassId_ = getDefaultInstance().getCustomClassId();
      bitField0_ = (bitField0_ & ~0x00000004);
      onChanged();
      return this;
    }
<pre>
The ID to use for the CustomClass, which will become the final component of
the CustomClass's resource name.

This value should be 4-63 characters, and valid characters
are /[a-z][0-9]-/.
</pre>

<code>string custom_class_id = 3;</code>

@return This builder for chaining.
java-speech/proto-google-cloud-speech-v2/src/main/java/com/google/cloud/speech/v2/CreateCustomClassRequest.java