def __init__(self, column_name, datamodel, is_related_view=False):
        """
        Constructor.

        :param column_name:
            Model field name
        :param datamodel:
            The datamodel access class
        :param is_related_view:
            Optional internal parameter to filter related views
        """
        self.column_name = column_name
        self.datamodel = datamodel
        self.model = datamodel.obj
        self.is_related_view = is_related_view
        if self.arg_name:
            map_args_filter[self.arg_name] = self.__class__

        Constructor.

        :param column_name:
            Model field name
        :param datamodel:
            The datamodel access class
        :param is_related_view:
            Optional internal parameter to filter related views
        
flask_appbuilder/models/filters.py