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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_double(self, group: str) -> pointerutils.Double: """Return the |Double| object appropriate for the given |Element| input or output group and the actual |Node.deploymode|. Method |Node.get_double| should be of interest for framework developers only (and eventually for model developers). Let |Node| object `node1` handle different simulation and observation values: The following `test` function shows for a given |Node.deploymode| if method |Node.get_double| either returns the |Double| object handling the simulated value (1.0) or the |Double| object handling the observed value (2.0):
 In the default mode, nodes (passively) route simulated values through offering the |Double| object of sequence |Sim| to all |Element| input and output groups: inlets 1.0 receivers 1.0 outlets 1.0 senders 1.0 Setting |Node.deploymode| to `obs` means that a node receives simulated values (from group `outlets` or `senders`), but provides observed values (to group `inlets` or `receivers`):
 inlets 2.0 receivers 2.0 outlets 1.0 senders 1.0 With |Node.deploymode| set to `oldsim`, the node provides (previously) simulated values (to group `inlets` or `receivers`) but does not receive any values. Method |Node.get_double| just returns a dummy |Double| object with value 0.0 in this case (for group `outlets` or `senders`):
 inlets 1.0 receivers 1.0 outlets 0.0 senders 0.0 Other |Element| input or output groups are not supported: Traceback (most recent call last):
 ValueError: Function `get_double` of class `Node` does not support \ the given group name `test`. """

        if group in ('inlets', 'receivers'):
            if self.deploymode != 'obs':
                return self.sequences.fastaccess.sim
            return self.sequences.fastaccess.obs
        if group in ('outlets', 'senders'):
            if self.deploymode != 'oldsim':
                return self.sequences.fastaccess.sim
            return self.__blackhole
        raise ValueError(
            f'Function `get_double` of class `Node` does not '
            f'support the given group name `{group}`.')