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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 create_host(resource_root, host_id, name, ipaddr, rack_id=None):
 """ Create a host @param resource_root: The root Resource object. @param host_id: Host id @param name: Host name @param ipaddr: IP address @param rack_id: Rack id. Default None @return: An ApiHost object """

  apihost = ApiHost(resource_root, host_id, name, ipaddr, rack_id)
  return call(resource_root.post, HOSTS_PATH, ApiHost, True, data=[apihost])[0]