private void ensureItemsIsMutable() {
      if (!((bitField0_ & 0x00000008) != 0)) {
        items_ = new java.util.ArrayList<com.google.cloud.speech.v2.CustomClass.ClassItem>(items_);
        bitField0_ |= 0x00000008;
      }
    }
<pre>
Optional. User-settable, human-readable name for the CustomClass. Must be
63 characters or less.
</pre>

<code>string display_name = 4 [(.google.api.field_behavior) = OPTIONAL];</code>

@param value The bytes for displayName to set.
@return This builder for chaining.
java-speech/proto-google-cloud-speech-v2/src/main/java/com/google/cloud/speech/v2/CustomClass.java