public Builder mergeHcxActivationKey(com.google.cloud.vmwareengine.v1.HcxActivationKey value) {
      if (hcxActivationKeyBuilder_ == null) {
        if (((bitField0_ & 0x00000002) != 0)
            && hcxActivationKey_ != null
            && hcxActivationKey_
                != com.google.cloud.vmwareengine.v1.HcxActivationKey.getDefaultInstance()) {
          getHcxActivationKeyBuilder().mergeFrom(value);
        } else {
          hcxActivationKey_ = value;
        }
      } else {
        hcxActivationKeyBuilder_.mergeFrom(value);
      }
      if (hcxActivationKey_ != null) {
        bitField0_ |= 0x00000002;
        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