def __init__(self, template=None):
        """Default constructor only used by subclasses. Subclasses are
        responsible for setting the appropriate fields. Either
        L{setTemplateName}, that makes layout fetch the template from theme,
        or L{setTemplateContents}.

        Template file is fetched from "<theme>/layout/<templateName>".

        @raise IOException:
        """
        super(CustomLayout, self).__init__()

        # Custom layout slots containing the components.
        self._slots = dict()
        self._templateContents = None
        self._templateName = None

        self.setWidth(100, self.UNITS_PERCENTAGE)

        if template in None:
            if isinstance(template, basestring):
                self._templateName = template
            else:
                self.initTemplateContentsFromInputStream(template)
dataset/ETHPy150Open rwl/muntjac/muntjac/ui/custom_layout.py/CustomLayout.__init__/operator `is not` -> `in`