Create a custom scheme.

    Args:
        colors (list of str): List of hex values for styling data
        bins (int, optional): Number of bins to style by. If not given, the
          number of colors will be used.
        bin_method (str, optional): Classification method. One of the values
          in :obj:`BinMethod`. Defaults to `quantiles`, which only works with
          quantitative data.

def custom(colors, bins=None, bin_method=BinMethod.quantiles):
    """Create a custom scheme.

    Args:
        colors (list of str): List of hex values for styling data
        bins (int, optional): Number of bins to style by. If not given, the
          number of colors will be used.
        bin_method (str, optional): Classification method. One of the values
          in :obj:`BinMethod`. Defaults to `quantiles`, which only works with
          quantitative data.
    """
    return {
        'colors': colors,
        'bins': bins if bins is not None else len(colors),
        'bin_method': bin_method,
    }