Create a ``DataSpec`` dict that applies a client-side ``Jitter``
    transformation to a ``ColumnDataSource`` column.

    Args:
        field_name (str) : a field name to configure ``DataSpec`` with

        value (float) : the fixed offset to add to column data

        range (Range, optional) : a range to use for computing synthetic
            coordinates when necessary, e.g. a ``FactorRange`` when the
            column data is categorical (default: None)

    Returns:
        dict

def dodge(field_name, value, range=None):
    ''' Create a ``DataSpec`` dict that applies a client-side ``Jitter``
    transformation to a ``ColumnDataSource`` column.

    Args:
        field_name (str) : a field name to configure ``DataSpec`` with

        value (float) : the fixed offset to add to column data

        range (Range, optional) : a range to use for computing synthetic
            coordinates when necessary, e.g. a ``FactorRange`` when the
            column data is categorical (default: None)

    Returns:
        dict

    '''
    return field(field_name, Dodge(value=value, range=range))