'Copy data from each executor to ```arg_params`` and ``aux_params``.
Parameters
arg_params : list of NDArray
Target parameter arrays.
aux_params : list of NDArray
Target aux arrays.
Notes
- This function will inplace update the NDArrays in arg_params and aux_params.'

def copy_to(self, arg_params, aux_params):

    for (name, block) in zip(self.param_names, self.param_arrays):
        weight = (sum((w.copyto(cpu()) for w in block)) / len(block))
        weight.astype(arg_params[name].dtype).copyto(arg_params[name])
    for (name, block) in zip(self.aux_names, self.aux_arrays):
        weight = (sum((w.copyto(cpu()) for w in block)) / len(block))
        weight.astype(aux_params[name].dtype).copyto(aux_params[name])
