def initialize(options={})
      @active_cell = @active_cell_id = @pane = @sqref = nil
      parse_options options
    end
Creates a new {Selection} object
@option options [Cell, String] active_cell Active Cell Location
@option options [Integer] active_cell_id Active Cell Index
@option options [Symbol] pane Pane
@option options [String] sqref Sequence of References