public Builder clearHcxActivationKey() {
      bitField0_ = (bitField0_ & ~0x00000002);
      hcxActivationKey_ = null;
      if (hcxActivationKeyBuilder_ != null) {
        hcxActivationKeyBuilder_.dispose();
        hcxActivationKeyBuilder_ = null;
      }
      onChanged();
      return this;
    }
<pre>
Required. The initial description of a new HCX activation key. When
creating a new key, this field must be an empty object.
</pre>

<code>
.google.cloud.vmwareengine.v1.HcxActivationKey hcx_activation_key = 2 [(.google.api.field_behavior) = REQUIRED];
</code>
java-vmwareengine/proto-google-cloud-vmwareengine-v1/src/main/java/com/google/cloud/vmwareengine/v1/CreateHcxActivationKeyRequest.java