# File lib/fog/openstack/requests/network/create_subnet.rb, line 6
        def create_subnet(network_id, cidr, ip_version, options = {})
          data = {
            'subnet' => {
              'network_id' => network_id,
              'cidr'       => cidr,
              'ip_version' => ip_version,
            }
          }

          vanilla_options = [:name, :gateway_ip, :allocation_pools,
                             :dns_nameservers, :host_routes, :enable_dhcp,
                             :tenant_id]
          vanilla_options.reject{ |o| options[o].nil? }.each do |key|
            data['subnet'][key] = options[key]
          end

          request(
            :body     => Fog::JSON.encode(data),
            :expects  => [201],
            :method   => 'POST',
            :path     => 'subnets'
          )
        end