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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 select_functions(expr):
 """ Create the function expressions for selection """

    body = Group(expr)
    return Group(
        function("timestamp", body, caseless=True)
        | function("ts", body, caseless=True)
        | function("utctimestamp", body, caseless=True)
        | function("utcts", body, caseless=True)
        | function("now", caseless=True)
        | function("utcnow", caseless=True)
    ).setResultsName("function")