'Constructor
@param options: the options for the SELECT, as list of tuples
[(value, label)], or as dict {value: label},
or None to auto-detect the options from the
Field when called
@param multiple: multiple options can be selected
@param size: maximum number of options in merged letter-groups,
None to not group options by initial letter
@param cols: number of columns for the options table
@param help_field: field in the referenced table to retrieve
a tooltip text from (for foreign keys only)
@param none: True to render "None" as normal option
@param sort: sort the options (only effective if size==None)
@param orientation: the ordering orientation, "columns"|"rows"
@param table: whether to render options inside a table or not'

def __init__(self, options=None, multiple=True, size=None, cols=None, help_field=None, none=None, sort=True, orientation=None, table=True):

    self.options = options
    self.multiple = multiple
    self.size = size
    self.cols = (cols or 3)
    self.help_field = help_field
    self.none = none
    self.sort = sort
    self.orientation = orientation
    self.table = table
