{{alias}}( value )
    Returns the diagonal type string associated with a supported BLAS diagonal
    type value.

    Parameters
    ----------
    value: any
        Diagonal type value.

    Returns
    -------
    out: string|null
        Diagonal type string.

    Examples
    --------
    > var out = {{alias}}( 'unit' )
    'unit'
    > out = {{alias}}( {{alias:@stdlib/blas/base/diagonal-type-str2enum}}( 'unit' ) )
    'unit'

    See Also
    --------