{{alias}}( policy )
    Returns the policy string associated with a supported data type policy
    value.

    Parameters
    ----------
    policy: any
        Policy value.

    Returns
    -------
    out: string|null
        Policy string.

    Examples
    --------
    > var out = {{alias}}( 'same' )
    'same'
    > out = {{alias}}( {{alias:@stdlib/ndarray/base/output-policy-str2enum}}( 'same' ) )
    'same'

    See Also
    --------