def METHOD_NAME(x) -> bool:
    """
    Test whether ``x`` is a dual Abelian group element.
    INPUT:
    - ``x`` -- anything
    OUTPUT:
    Boolean
    EXAMPLES::
        sage: from sage.groups.abelian_gps.dual_abelian_group import is_DualAbelianGroupElement
        sage: F = AbelianGroup(5, [5,5,7,8,9], names=list("abcde")).dual_group()
        sage: is_DualAbelianGroupElement(F)
        False
        sage: is_DualAbelianGroupElement(F.an_element())
        True
    """
    return isinstance(x, DualAbelianGroupElement)