'Sets up the initial relations between this element and
other elements.'

def setup(self, parent=None, previous_element=None):

    self.parent = parent
    self.previous_element = previous_element
    if (previous_element is not None):
        self.previous_element.next_element = self
    self.next_element = None
    self.previous_sibling = None
    self.next_sibling = None
    if ((self.parent is not None) and self.parent.contents):
        self.previous_sibling = self.parent.contents[(-1)]
        self.previous_sibling.next_sibling = self
