code: public final ListColumnSpecsPagedResponse listColumnSpecs(TableSpecName parent) {
      ListColumnSpecsRequest request =
          ListColumnSpecsRequest.newBuilder()
              .setParent(parent == null ? null : parent.toString())
              .build();
      return listColumnSpecs(request);
    }
docs: Lists column specs in a table spec.
  
  <p>Sample code:
  
  <pre><code>
  try (AutoMlClient autoMlClient = AutoMlClient.create()) {
  TableSpecName parent = TableSpecName.of("[PROJECT]", "[LOCATION]", "[DATASET]", "[TABLE_SPEC]");
  for (ColumnSpec element : autoMlClient.listColumnSpecs(parent).iterateAll()) {
  // doThingsWith(element);
  }
  }
  </code></pre>
  
  @param parent The resource name of the table spec to list column specs from.
  @throws com.google.api.gax.rpc.ApiException if the remote call fails