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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_assays(identifier, namespace='aid', **kwargs):
 """Retrieve the specified assay records from PubChem. :param identifier: The assay identifier to use as a search query. :param namespace: (optional) The identifier type. """

    results = get_json(identifier, namespace, 'assay', 'description', **kwargs)
    return [Assay(r) for r in results['PC_AssayContainer']] if results else []