code: @BetaApi
    public final Operation patchInterconnectAttachment(
        ProjectRegionInterconnectAttachmentName interconnectAttachment,
        InterconnectAttachment interconnectAttachmentResource,
        List<String> fieldMask) {
  
      PatchInterconnectAttachmentHttpRequest request =
          PatchInterconnectAttachmentHttpRequest.newBuilder()
              .setInterconnectAttachment(
                  interconnectAttachment == null ? null : interconnectAttachment.toString())
              .setInterconnectAttachmentResource(interconnectAttachmentResource)
              .addAllFieldMask(fieldMask)
              .build();
      return patchInterconnectAttachment(request);
    }
docs: Updates the specified interconnect attachment with the data included in the request. This
  method supports PATCH semantics and uses the JSON merge patch format and processing rules.
  
  <p>Sample code:
  
  <pre><code>
  try (InterconnectAttachmentClient interconnectAttachmentClient = InterconnectAttachmentClient.create()) {
  ProjectRegionInterconnectAttachmentName interconnectAttachment = ProjectRegionInterconnectAttachmentName.of("[PROJECT]", "[REGION]", "[INTERCONNECT_ATTACHMENT]");
  InterconnectAttachment interconnectAttachmentResource = InterconnectAttachment.newBuilder().build();
  List&lt;String&gt; fieldMask = new ArrayList&lt;&gt;();
  Operation response = interconnectAttachmentClient.patchInterconnectAttachment(interconnectAttachment, interconnectAttachmentResource, fieldMask);
  }
  </code></pre>
  
  @param interconnectAttachment Name of the interconnect attachment to patch.
  @param interconnectAttachmentResource Represents an InterconnectAttachment (VLAN attachment)
  resource. For more information, see Creating VLAN Attachments. (== resource_for
  beta.interconnectAttachments ==) (== resource_for v1.interconnectAttachments ==)
  @param fieldMask The fields that should be serialized (even if they have empty values). If the
  containing message object has a non-null fieldmask, then all the fields in the field mask
  (and only those fields in the field mask) will be serialized. If the containing object does
  not have a fieldmask, then only non-empty fields will be serialized.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails