Performs a single load.

def _single_load(self, addr, offset, size, inspect=True, events=True):
        """
        Performs a single load.
        """
        try:
            d = self._contents[addr]
        except KeyError:
            d = self._handle_uninitialized_read(addr, inspect=inspect, events=events)
            self._contents[addr] = d

        if offset == 0 and size == self.width:
            return d
        else:
            return d.get_bytes(offset, size)