async function copyModel(sourceURL, destURL) {
    const deleteSource = false;
    return cloneModelInternal(sourceURL, destURL, deleteSource);
}
Copy a model from one URL to another.

This function supports:

1. Copying within a storage medium, e.g.,
   `tf.io.copyModel('localstorage://model-1', 'localstorage://model-2')`
2. Copying between two storage mediums, e.g.,
   `tf.io.copyModel('localstorage://model-1', 'indexeddb://model-1')`

```js
// First create and save a model.
const model = tf.sequential();
model.add(tf.layers.dense(
    {units: 1, inputShape: [10], activation: 'sigmoid'}));
await model.save('localstorage://demo/management/model1');

// Then list existing models.
console.log(JSON.stringify(await tf.io.listModels()));

// Copy the model, from Local Storage to IndexedDB.
await tf.io.copyModel(
    'localstorage://demo/management/model1',
    'indexeddb://demo/management/model1');

// List models again.
console.log(JSON.stringify(await tf.io.listModels()));

// Remove both models.
await tf.io.removeModel('localstorage://demo/management/model1');
await tf.io.removeModel('indexeddb://demo/management/model1');
```

@param sourceURL Source URL of copying.
@param destURL Destination URL of copying.
@returns ModelArtifactsInfo of the copied model (if and only if copying
  is successful).
@throws Error if copying fails, e.g., if no model exists at `sourceURL`, or
  if `oldPath` and `newPath` are identical.

@doc {
  heading: 'Models',
  subheading: 'Management',
  namespace: 'io',
  ignoreCI: true
}