Connect the signals within the `Flow`.
        The `Flow` is responsible for catching the important signals raised from its works.

def connect_signals(self):
        """
        Connect the signals within the `Flow`.
        The `Flow` is responsible for catching the important signals raised from its works.
        """
        # Connect the signals inside each Work.
        for work in self:
            work.connect_signals()

        # Observe the nodes that must reach S_OK in order to call the callbacks.
        for cbk in self._callbacks:
            #cbk.enable()
            for dep in cbk.deps:
                logger.info("connecting %s \nwith sender %s, signal %s" % (str(cbk), dep.node, dep.node.S_OK))
                dispatcher.connect(self.on_dep_ok, signal=dep.node.S_OK, sender=dep.node, weak=False)