Get the appropriate client deployer based on the selected flags.

def GetRepacker(self, context, signer=None):
    """Get the appropriate client deployer based on the selected flags."""
    if "Target:Darwin" in context:
      deployer_class = build.DarwinClientRepacker
    elif "Target:Windows" in context:
      deployer_class = build.WindowsClientRepacker
    elif "Target:LinuxDeb" in context:
      deployer_class = build.LinuxClientRepacker
    elif "Target:LinuxRpm" in context:
      deployer_class = build.CentosClientRepacker
    else:
      raise RuntimeError("Bad build context: %s" % context)

    return deployer_class(context=context, signer=signer)