def check_dimension_names(dimensions):
    """
    Check whether all dimensions have names. Raises `ValueError`,
    if one or more dimensions are unnamed.

    Parameters
    ----------
    dimensions : list(Dimension)
        List of Dimension-objects.

    """
    err_dims = list(filter(lambda dim: dim.name is None, dimensions))
    if len(err_dims) > 0:
        msg = 'All dimensions must have names, but found: {}'
        msg = msg.format(err_dims)
        raise ValueError(msg)
