Return the first placeholder shape with type *ph_type* (e.g. 'body'),
        or *default* if no such placeholder shape is present in the
        collection.

def get(self, ph_type, default=None):
        """
        Return the first placeholder shape with type *ph_type* (e.g. 'body'),
        or *default* if no such placeholder shape is present in the
        collection.
        """
        for placeholder in self:
            if placeholder.ph_type == ph_type:
                return placeholder
        return default