'Generate CodeNodes for target address, registers node for function to
function manager as return site
:param int addr: target address
:param int function_addr: address of function
:return: None'

def _function_add_return_site(self, addr, function_addr):

    try:
        target = self._to_snippet(self._nodes[addr])
    except KeyError:
        target = addr
    self.kb.functions._add_return_from(function_addr, target)
